<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:42ca7542-5a74-4a57-8913-d9ee14ee6bd6,g:4e5edd70-bfc8-4901-9bf5-215085982d34-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUnaudited" xlink:type="simple" xlink:href="sncr-20250630.xsd#CONDENSEDCONSOLIDATEDBALANCESHEETSUnaudited"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_e0362e09-3f3d-420d-8f99-b627dc3d26c6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_041235e4-f5fb-4700-92d2-567e8c87ab90" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_e0362e09-3f3d-420d-8f99-b627dc3d26c6" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_041235e4-f5fb-4700-92d2-567e8c87ab90" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_d7bc1b5c-cbd3-4bbf-99d8-f178cb77a00c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_e0362e09-3f3d-420d-8f99-b627dc3d26c6" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_d7bc1b5c-cbd3-4bbf-99d8-f178cb77a00c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_b79129e3-e016-4caa-964f-c1d337c5f1df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_e0362e09-3f3d-420d-8f99-b627dc3d26c6" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_b79129e3-e016-4caa-964f-c1d337c5f1df" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_efa0b5ea-a102-412b-8722-b11718867604" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_e0362e09-3f3d-420d-8f99-b627dc3d26c6" xlink:to="loc_us-gaap_LiabilitiesCurrent_efa0b5ea-a102-412b-8722-b11718867604" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_LeaseLiabilityNoncurrent_40217d1d-2fda-465b-90ef-78aa308238ae" xlink:href="sncr-20250630.xsd#sncr_LeaseLiabilityNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_e0362e09-3f3d-420d-8f99-b627dc3d26c6" xlink:to="loc_sncr_LeaseLiabilityNoncurrent_40217d1d-2fda-465b-90ef-78aa308238ae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrent_534e5592-cb34-4c5c-b9cd-d86197238ee8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsNoncurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_e52dc153-04c4-4f0b-a56e-0665862a8d5d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsNoncurrent_534e5592-cb34-4c5c-b9cd-d86197238ee8" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_e52dc153-04c4-4f0b-a56e-0665862a8d5d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_78ce562f-12a4-4493-8d52-52a8a05387dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsNoncurrent_534e5592-cb34-4c5c-b9cd-d86197238ee8" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_78ce562f-12a4-4493-8d52-52a8a05387dc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_f9bb6160-7438-41e9-bff4-2992a8cb8818" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsNoncurrent_534e5592-cb34-4c5c-b9cd-d86197238ee8" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_f9bb6160-7438-41e9-bff4-2992a8cb8818" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_16a60d95-24df-4909-876f-bcf6327c7b6a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsNoncurrent_534e5592-cb34-4c5c-b9cd-d86197238ee8" xlink:to="loc_us-gaap_Goodwill_16a60d95-24df-4909-876f-bcf6327c7b6a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_16309204-c503-4c65-965b-c787d3001dee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsNoncurrent_534e5592-cb34-4c5c-b9cd-d86197238ee8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_16309204-c503-4c65-965b-c787d3001dee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_70b553d7-2149-4966-b396-e1bad5c7f642" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_7abce6fc-2120-4036-a6c8-6c2c7879809b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_70b553d7-2149-4966-b396-e1bad5c7f642" xlink:to="loc_us-gaap_AccountsPayableCurrent_7abce6fc-2120-4036-a6c8-6c2c7879809b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_633ae8c8-8bce-4c1e-a4d7-a7dd9064f016" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_70b553d7-2149-4966-b396-e1bad5c7f642" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_633ae8c8-8bce-4c1e-a4d7-a7dd9064f016" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_dd45c112-e721-40f0-b39c-1f8971090819" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_70b553d7-2149-4966-b396-e1bad5c7f642" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_dd45c112-e721-40f0-b39c-1f8971090819" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtCurrent_280c4790-b2f8-47b1-a2e7-13095aa86fbf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_70b553d7-2149-4966-b396-e1bad5c7f642" xlink:to="loc_us-gaap_DebtCurrent_280c4790-b2f8-47b1-a2e7-13095aa86fbf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_7108ff3d-99d7-416a-83a4-3f5e8bcd08b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_f9504144-c434-42bc-bbbf-4167c0728a02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_7108ff3d-99d7-416a-83a4-3f5e8bcd08b0" xlink:to="loc_us-gaap_CommonStockValue_f9504144-c434-42bc-bbbf-4167c0728a02" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_710f409a-3045-4aa8-90c7-554cf311f593" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_7108ff3d-99d7-416a-83a4-3f5e8bcd08b0" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_710f409a-3045-4aa8-90c7-554cf311f593" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_89323684-e095-4a0e-9fe7-4e076236e400" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_7108ff3d-99d7-416a-83a4-3f5e8bcd08b0" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_89323684-e095-4a0e-9fe7-4e076236e400" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_909eb3a0-c8ce-44bb-aca5-e9da2131233c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_7108ff3d-99d7-416a-83a4-3f5e8bcd08b0" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_909eb3a0-c8ce-44bb-aca5-e9da2131233c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_d51cb29f-c822-4c02-a22f-fc5664a44398" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_ba24e882-1700-48cd-91f2-c75811cc814c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_d51cb29f-c822-4c02-a22f-fc5664a44398" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_ba24e882-1700-48cd-91f2-c75811cc814c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_9add74e8-ccdb-434c-bee1-e38d22a9ec6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_d51cb29f-c822-4c02-a22f-fc5664a44398" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_9add74e8-ccdb-434c-bee1-e38d22a9ec6d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_98793396-797e-4665-88ac-e5f80ab532ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_d51cb29f-c822-4c02-a22f-fc5664a44398" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_98793396-797e-4665-88ac-e5f80ab532ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_46da9bbe-300a-4d53-9c0c-d5ced4e5d456" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrent_ef99617b-e4b8-462b-92ed-8959f828fe4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_46da9bbe-300a-4d53-9c0c-d5ced4e5d456" xlink:to="loc_us-gaap_AssetsNoncurrent_ef99617b-e4b8-462b-92ed-8959f828fe4e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_05576470-87c8-49e7-8a04-e27022af3d06" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_46da9bbe-300a-4d53-9c0c-d5ced4e5d456" xlink:to="loc_us-gaap_AssetsCurrent_05576470-87c8-49e7-8a04-e27022af3d06" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_27ef5fb9-ea36-4d3b-a46a-93e8c17e5760" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_3d32648c-3863-418d-a098-4903f48934d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_27ef5fb9-ea36-4d3b-a46a-93e8c17e5760" xlink:to="loc_us-gaap_StockholdersEquity_3d32648c-3863-418d-a098-4903f48934d9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_759147cf-7256-48a2-935d-2083207d4fb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_27ef5fb9-ea36-4d3b-a46a-93e8c17e5760" xlink:to="loc_us-gaap_CommitmentsAndContingencies_759147cf-7256-48a2-935d-2083207d4fb2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_98657919-cfda-4161-bede-c68b90ecfc1c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_27ef5fb9-ea36-4d3b-a46a-93e8c17e5760" xlink:to="loc_us-gaap_Liabilities_98657919-cfda-4161-bede-c68b90ecfc1c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_7860962a-9158-4897-87ba-fc95009f67b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_27ef5fb9-ea36-4d3b-a46a-93e8c17e5760" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_7860962a-9158-4897-87ba-fc95009f67b9" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSUnaudited" xlink:type="simple" xlink:href="sncr-20250630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSUnaudited"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFOPERATIONSUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_0fc6573e-d1ea-4660-93ff-dc592fb8748a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_4f456a51-33f4-451c-a8d4-35e7e929fc56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_0fc6573e-d1ea-4660-93ff-dc592fb8748a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_4f456a51-33f4-451c-a8d4-35e7e929fc56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_7adaa624-0fc3-49d5-9001-87da9dd7b1e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpenses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_0fc6573e-d1ea-4660-93ff-dc592fb8748a" xlink:to="loc_us-gaap_CostsAndExpenses_7adaa624-0fc3-49d5-9001-87da9dd7b1e6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_3e80d765-efdc-4f83-a6a0-e7df0877c88b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:to="loc_us-gaap_InvestmentIncomeInterest_3e80d765-efdc-4f83-a6a0-e7df0877c88b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_DebtModificationExpense_6b6386f0-6e99-4135-80cf-6eb9b4aab953" xlink:href="sncr-20250630.xsd#sncr_DebtModificationExpense"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:to="loc_sncr_DebtModificationExpense_6b6386f0-6e99-4135-80cf-6eb9b4aab953" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_a9ff6b5e-b4b9-470a-8a17-ffa8a57ae39d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:to="loc_us-gaap_InterestExpenseNonoperating_a9ff6b5e-b4b9-470a-8a17-ffa8a57ae39d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_49d1079f-9748-4444-a88d-d300516944f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_49d1079f-9748-4444-a88d-d300516944f7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_94c6abfe-51c1-463a-ac97-23c581223dd7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_94c6abfe-51c1-463a-ac97-23c581223dd7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingIncomeExpenseNet_5af57786-fb06-4b5d-8a4a-5acd0b65bfd2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherOperatingIncomeExpenseNet"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:to="loc_us-gaap_OtherOperatingIncomeExpenseNet_5af57786-fb06-4b5d-8a4a-5acd0b65bfd2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_0979fffb-9252-4c46-b2dc-3b6674132d2e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_36719e6b-f66b-4d3b-bf1d-1e00c2e76530" xlink:to="loc_us-gaap_OperatingIncomeLoss_0979fffb-9252-4c46-b2dc-3b6674132d2e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_253b9fdf-5b6d-44ee-8a5e-61f73bbe3656" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_PreferredStockDividend_de395c4a-bbfe-4b5a-827c-623181b7fa5d" xlink:href="sncr-20250630.xsd#sncr_PreferredStockDividend"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_253b9fdf-5b6d-44ee-8a5e-61f73bbe3656" xlink:to="loc_sncr_PreferredStockDividend_de395c4a-bbfe-4b5a-827c-623181b7fa5d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_4cebddca-2d29-494d-9684-fd573bb41466" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_253b9fdf-5b6d-44ee-8a5e-61f73bbe3656" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_4cebddca-2d29-494d-9684-fd573bb41466" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_938bc6cf-fd25-4bf3-a35d-0826aca2ffe4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_253b9fdf-5b6d-44ee-8a5e-61f73bbe3656" xlink:to="loc_us-gaap_ProfitLoss_938bc6cf-fd25-4bf3-a35d-0826aca2ffe4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_84488185-753c-4b1c-9798-1c5229075efa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_4d2f262c-4736-4b4c-8824-18ab49ec2a58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLoss_84488185-753c-4b1c-9798-1c5229075efa" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_4d2f262c-4736-4b4c-8824-18ab49ec2a58" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_b2f7f723-2538-4b14-b0e0-3dcc6d90c451" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLoss_84488185-753c-4b1c-9798-1c5229075efa" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_b2f7f723-2538-4b14-b0e0-3dcc6d90c451" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_76d4d5c3-83b5-435e-bf5b-628ef54600b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_e0e76316-2de8-4d82-bc52-802567b33772" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_76d4d5c3-83b5-435e-bf5b-628ef54600b5" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_e0e76316-2de8-4d82-bc52-802567b33772" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_814dbf52-c7a6-4565-9fe4-a29c389f5782" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_76d4d5c3-83b5-435e-bf5b-628ef54600b5" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_814dbf52-c7a6-4565-9fe4-a29c389f5782" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_cb5c7894-3874-4872-835b-fe038442e19a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_76d4d5c3-83b5-435e-bf5b-628ef54600b5" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_cb5c7894-3874-4872-835b-fe038442e19a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_52ee4883-8305-49fe-b3b4-514f68aecfed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringCharges"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_76d4d5c3-83b5-435e-bf5b-628ef54600b5" xlink:to="loc_us-gaap_RestructuringCharges_52ee4883-8305-49fe-b3b4-514f68aecfed" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_a47fe6ba-a10f-4fb8-8783-66f068ff1c80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_76d4d5c3-83b5-435e-bf5b-628ef54600b5" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_a47fe6ba-a10f-4fb8-8783-66f068ff1c80" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSSUnaudited" xlink:type="simple" xlink:href="sncr-20250630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSSUnaudited"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSSUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_566fea28-f635-47e8-81ce-1ce475868353" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_0f4f81f0-92f7-485a-a4e9-9b735e62c803" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_566fea28-f635-47e8-81ce-1ce475868353" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_0f4f81f0-92f7-485a-a4e9-9b735e62c803" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_5c19a03e-d08b-4cfd-b43b-03603a7a3c18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_566fea28-f635-47e8-81ce-1ce475868353" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest_5c19a03e-d08b-4cfd-b43b-03603a7a3c18" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_4fb2ae6b-5496-4ca7-8ceb-954167cb29d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_2440a309-b01e-43ad-8656-98217ac56042" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_4fb2ae6b-5496-4ca7-8ceb-954167cb29d2" xlink:to="loc_us-gaap_ProfitLoss_2440a309-b01e-43ad-8656-98217ac56042" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_65df5c91-7ceb-40ab-a0e7-79acadde2402" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_4fb2ae6b-5496-4ca7-8ceb-954167cb29d2" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_65df5c91-7ceb-40ab-a0e7-79acadde2402" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited" xlink:type="simple" xlink:href="sncr-20250630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_e15a174a-7bc7-4a8c-954b-f03f52e4db52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_e15a174a-7bc7-4a8c-954b-f03f52e4db52" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_DepreciationDepletionAndAmortizationNetOfImpairment_fb82b2d8-b4bc-47ec-b303-77fa46967825" xlink:href="sncr-20250630.xsd#sncr_DepreciationDepletionAndAmortizationNetOfImpairment"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_sncr_DepreciationDepletionAndAmortizationNetOfImpairment_fb82b2d8-b4bc-47ec-b303-77fa46967825" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_d49e019a-08cb-47ef-8844-a29efb58a3d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_d49e019a-08cb-47ef-8844-a29efb58a3d5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_0a648204-83b7-4785-9e74-f7bcbc375597" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_0a648204-83b7-4785-9e74-f7bcbc375597" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_SubleaseReceivableImpairment_f8ccfb68-cba8-4ab1-8ff1-645dbc6b635e" xlink:href="sncr-20250630.xsd#sncr_SubleaseReceivableImpairment"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_sncr_SubleaseReceivableImpairment_f8ccfb68-cba8-4ab1-8ff1-645dbc6b635e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_73f080e8-f9fa-45a3-a315-2db375b4eee6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_73f080e8-f9fa-45a3-a315-2db375b4eee6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_0a154b74-373a-4fe9-ba17-0a1c15235054" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_0a154b74-373a-4fe9-ba17-0a1c15235054" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_73f7b740-12c8-41fd-9d19-812f63f7ae56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_73f7b740-12c8-41fd-9d19-812f63f7ae56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_46fe3478-6b86-496f-bc46-9a670c729b69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_46fe3478-6b86-496f-bc46-9a670c729b69" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_6f2c2905-79a1-4188-b8ce-b0648bd28aad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_6f2c2905-79a1-4188-b8ce-b0648bd28aad" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_6570a72a-555c-47e0-a42d-59080076fd43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_6570a72a-555c-47e0-a42d-59080076fd43" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_7de06830-2564-415e-ac17-7fa924458dde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_7de06830-2564-415e-ac17-7fa924458dde" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_699f25fb-d7bc-428c-9a99-2df9aefc0f62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_699f25fb-d7bc-428c-9a99-2df9aefc0f62" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_1ff87aed-d45e-4966-86b1-d6c76619b16d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_1ff87aed-d45e-4966-86b1-d6c76619b16d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_a303edb2-c034-4072-8f28-6a09f1941cf9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_ShareBasedCompensation_a303edb2-c034-4072-8f28-6a09f1941cf9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_21e16fd6-cf88-4abb-9fc0-28091e399fbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
    <link:calculationArc order="16" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_87ac86b0-bef7-4b5f-8547-ebd2f1011218" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_21e16fd6-cf88-4abb-9fc0-28091e399fbd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_58c2de9f-b728-4476-9e68-61a58046fd5f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_5a0cead3-3e16-454c-8c0c-c5a0e80530e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_58c2de9f-b728-4476-9e68-61a58046fd5f" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_5a0cead3-3e16-454c-8c0c-c5a0e80530e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_52f70ac4-c1ed-440d-bc17-5662ff821838" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_58c2de9f-b728-4476-9e68-61a58046fd5f" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_52f70ac4-c1ed-440d-bc17-5662ff821838" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_2523e595-dcd6-48be-86e8-12a7b8a95212" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_58c2de9f-b728-4476-9e68-61a58046fd5f" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_2523e595-dcd6-48be-86e8-12a7b8a95212" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_c33cd32e-9701-4e15-9b61-8a45f3f4e406" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_58c2de9f-b728-4476-9e68-61a58046fd5f" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_c33cd32e-9701-4e15-9b61-8a45f3f4e406" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_0c4051cb-2978-40cd-99a4-8cd08e8a6671" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_0bebedb0-b78e-4d0f-a51a-81c22ebfcd47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_0c4051cb-2978-40cd-99a4-8cd08e8a6671" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_0bebedb0-b78e-4d0f-a51a-81c22ebfcd47" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForSoftware_c79a4ccb-7468-4a04-a06b-81f574c40ade" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForSoftware"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_0c4051cb-2978-40cd-99a4-8cd08e8a6671" xlink:to="loc_us-gaap_PaymentsForSoftware_c79a4ccb-7468-4a04-a06b-81f574c40ade" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_ShareBasedCompensationRelatedProceeds_becfde13-28ad-41b1-ae5a-402025f9ee18" xlink:href="sncr-20250630.xsd#sncr_ShareBasedCompensationRelatedProceeds"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_sncr_ShareBasedCompensationRelatedProceeds_becfde13-28ad-41b1-ae5a-402025f9ee18" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_9939f3e3-e636-4978-a91b-5c76b2e30761" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_9939f3e3-e636-4978-a91b-5c76b2e30761" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_a780def2-93bb-4acb-bc3c-6f8b8e6a6a02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_a780def2-93bb-4acb-bc3c-6f8b8e6a6a02" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_a28b8f2e-c78c-46e2-a7c0-18ba38340253" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_a28b8f2e-c78c-46e2-a7c0-18ba38340253" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_2547cf4b-472a-4c71-9479-b3940888bb39" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_2547cf4b-472a-4c71-9479-b3940888bb39" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_RetirementOfSeniorNotes_5811fa36-5f95-4ad3-9cd4-33f7de691c2d" xlink:href="sncr-20250630.xsd#sncr_RetirementOfSeniorNotes"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_sncr_RetirementOfSeniorNotes_5811fa36-5f95-4ad3-9cd4-33f7de691c2d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_335811d9-69d0-422b-81a8-1389863442f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDebtExtinguishmentCosts"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_335811d9-69d0-422b-81a8-1389863442f7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_ProceedsFromAccountsReceivableFacility_115f3c5a-24fe-405a-ac65-ad0513c7a3d7" xlink:href="sncr-20250630.xsd#sncr_ProceedsFromAccountsReceivableFacility"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_sncr_ProceedsFromAccountsReceivableFacility_115f3c5a-24fe-405a-ac65-ad0513c7a3d7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_RepaymentsOfAccountsReceivableFacility_eeaac24d-a8c3-4521-8d94-02354ce528c6" xlink:href="sncr-20250630.xsd#sncr_RepaymentsOfAccountsReceivableFacility"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_sncr_RepaymentsOfAccountsReceivableFacility_eeaac24d-a8c3-4521-8d94-02354ce528c6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_df3235b2-fb9b-4e10-a29b-88dda1d7dfce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_df3235b2-fb9b-4e10-a29b-88dda1d7dfce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfRedeemableConvertiblePreferredStock_9fa91a0c-16a3-4118-a780-a45659c69703" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfRedeemableConvertiblePreferredStock"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_4b2c7b96-518f-4d99-8a25-2d5b0a8dd3ff" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfRedeemableConvertiblePreferredStock_9fa91a0c-16a3-4118-a780-a45659c69703" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/FairValueMeasurementsDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#FairValueMeasurementsDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/FairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_d3cc0ec9-7e94-439d-b13e-509a908ca26c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_f83e17c2-34cf-4439-9a2c-3301ef87f49b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_d3cc0ec9-7e94-439d-b13e-509a908ca26c" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_f83e17c2-34cf-4439-9a2c-3301ef87f49b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_711e9e7d-83f8-434e-806d-07c25d331fec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent_351e9682-eba5-4ce1-80bb-3e27cb84f78a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_711e9e7d-83f8-434e-806d-07c25d331fec" xlink:to="loc_us-gaap_DeferredCompensationShareBasedArrangementsLiabilityCurrent_351e9682-eba5-4ce1-80bb-3e27cb84f78a" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/LeasesScheduleofCompanysRightOfUseROUAssetsandLeaseLiabilitiesDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#LeasesScheduleofCompanysRightOfUseROUAssetsandLeaseLiabilitiesDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/LeasesScheduleofCompanysRightOfUseROUAssetsandLeaseLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_284d44db-bea2-49ea-931b-e22f022fc5b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_fa4b08d1-d561-46bb-b7cc-5f4aa31ebb9e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeaseLiability_284d44db-bea2-49ea-931b-e22f022fc5b9" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_fa4b08d1-d561-46bb-b7cc-5f4aa31ebb9e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_95564a91-8389-4de7-a01e-43dc4734bece" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeaseLiability_284d44db-bea2-49ea-931b-e22f022fc5b9" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_95564a91-8389-4de7-a01e-43dc4734bece" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_de4fbb9e-e873-4f36-9abd-14edc754fa28" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityCurrent_d0d7a6f7-b997-4ba8-b31a-31da14d28cbc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiability_de4fbb9e-e873-4f36-9abd-14edc754fa28" xlink:to="loc_us-gaap_FinanceLeaseLiabilityCurrent_d0d7a6f7-b997-4ba8-b31a-31da14d28cbc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_4a229623-e313-44a8-872c-08ccc83baa93" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiability_de4fbb9e-e873-4f36-9abd-14edc754fa28" xlink:to="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_4a229623-e313-44a8-872c-08ccc83baa93" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/LeasesScheduleofComponentsofLeaseExpenseDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#LeasesScheduleofComponentsofLeaseExpenseDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/LeasesScheduleofComponentsofLeaseExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost_b665f4e8-7f71-4eeb-b517-aeded6d29af3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome_c714e338-fda9-4347-a5cc-cd58a902afae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubleaseIncome"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_b665f4e8-7f71-4eeb-b517-aeded6d29af3" xlink:to="loc_us-gaap_SubleaseIncome_c714e338-fda9-4347-a5cc-cd58a902afae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableLeaseCost_4dbdb25f-5a1c-467c-988b-4337b9e8d39e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableLeaseCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_b665f4e8-7f71-4eeb-b517-aeded6d29af3" xlink:to="loc_us-gaap_VariableLeaseCost_4dbdb25f-5a1c-467c-988b-4337b9e8d39e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost_f22eecef-b1cd-4244-87e7-b2343e538c43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_b665f4e8-7f71-4eeb-b517-aeded6d29af3" xlink:to="loc_us-gaap_OperatingLeaseCost_f22eecef-b1cd-4244-87e7-b2343e538c43" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_845d232b-ffdd-46e3-8f66-7f2936ff234c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_b665f4e8-7f71-4eeb-b517-aeded6d29af3" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_845d232b-ffdd-46e3-8f66-7f2936ff234c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_LeaseCostNet_78053a8f-7242-4dc4-9550-1d46a083a6ee" xlink:href="sncr-20250630.xsd#sncr_LeaseCostNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_FinanceLeaseExpense_53052b65-1146-4364-9b4a-9d397bd5f6a9" xlink:href="sncr-20250630.xsd#sncr_FinanceLeaseExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sncr_LeaseCostNet_78053a8f-7242-4dc4-9550-1d46a083a6ee" xlink:to="loc_sncr_FinanceLeaseExpense_53052b65-1146-4364-9b4a-9d397bd5f6a9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost_e82e4642-4dc7-488e-b053-659185e7eee3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sncr_LeaseCostNet_78053a8f-7242-4dc4-9550-1d46a083a6ee" xlink:to="loc_us-gaap_LeaseCost_e82e4642-4dc7-488e-b053-659185e7eee3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_FinanceLeaseExpense_02157415-0f97-433e-a51a-6ca69fa23369" xlink:href="sncr-20250630.xsd#sncr_FinanceLeaseExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestExpense_e7d36c6d-3246-4fdd-8495-9ad5cd772d09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sncr_FinanceLeaseExpense_02157415-0f97-433e-a51a-6ca69fa23369" xlink:to="loc_us-gaap_FinanceLeaseInterestExpense_e7d36c6d-3246-4fdd-8495-9ad5cd772d09" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_FinanceLeaseDepreciationExpense_0e012785-3707-47a2-8723-bef14ab8eed3" xlink:href="sncr-20250630.xsd#sncr_FinanceLeaseDepreciationExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_sncr_FinanceLeaseExpense_02157415-0f97-433e-a51a-6ca69fa23369" xlink:to="loc_sncr_FinanceLeaseDepreciationExpense_0e012785-3707-47a2-8723-bef14ab8eed3" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/LeasesScheduleofReconciliationofSuchUndiscountedCashFlowstoOurLeaseLiabilitiesDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#LeasesScheduleofReconciliationofSuchUndiscountedCashFlowstoOurLeaseLiabilitiesDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/LeasesScheduleofReconciliationofSuchUndiscountedCashFlowstoOurLeaseLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_de67b8a5-5300-47d9-85ed-22b3c26260ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_480fdc82-271d-49ea-9640-54544070fc74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_de67b8a5-5300-47d9-85ed-22b3c26260ac" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_480fdc82-271d-49ea-9640-54544070fc74" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_6cd74738-56a0-475e-ad41-5b4d5efaa1d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_de67b8a5-5300-47d9-85ed-22b3c26260ac" xlink:to="loc_us-gaap_OperatingLeaseLiability_6cd74738-56a0-475e-ad41-5b4d5efaa1d5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_6ba5d213-3f69-42cc-be75-90327d1eadb2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_0f072518-9ea4-4bc9-ad16-92c3c6e7f14f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_6ba5d213-3f69-42cc-be75-90327d1eadb2" xlink:to="loc_us-gaap_FinanceLeaseLiability_0f072518-9ea4-4bc9-ad16-92c3c6e7f14f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_8d51a689-2426-47b6-aede-eb5f412d8340" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_6ba5d213-3f69-42cc-be75-90327d1eadb2" xlink:to="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_8d51a689-2426-47b6-aede-eb5f412d8340" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/LeasesScheduleofReconciliationofSuchUndiscountedCashFlowstoOurLeaseLiabilitiesDetails_1" xlink:type="simple" xlink:href="sncr-20250630.xsd#LeasesScheduleofReconciliationofSuchUndiscountedCashFlowstoOurLeaseLiabilitiesDetails_1"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/LeasesScheduleofReconciliationofSuchUndiscountedCashFlowstoOurLeaseLiabilitiesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_0ad5bd5b-8f14-4008-a4fe-2e8930c956a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_f7380179-7e7b-42f4-a55e-122b56963e4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_0ad5bd5b-8f14-4008-a4fe-2e8930c956a2" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_f7380179-7e7b-42f4-a55e-122b56963e4a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_3517973e-f8ab-462d-b5dc-ccd3340b5d20" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_0ad5bd5b-8f14-4008-a4fe-2e8930c956a2" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_3517973e-f8ab-462d-b5dc-ccd3340b5d20" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_c3ddb55d-7442-402d-abd1-1cc38ca5c1e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_0ad5bd5b-8f14-4008-a4fe-2e8930c956a2" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_c3ddb55d-7442-402d-abd1-1cc38ca5c1e3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_e42e0acb-0b3f-488d-9cef-66a431bb10f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_0ad5bd5b-8f14-4008-a4fe-2e8930c956a2" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_e42e0acb-0b3f-488d-9cef-66a431bb10f8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_d0587ee0-170d-410e-bd67-8d8eb4f8eb23" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_5c621534-1a15-40a5-bf27-0a21ec9aa884" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_d0587ee0-170d-410e-bd67-8d8eb4f8eb23" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_5c621534-1a15-40a5-bf27-0a21ec9aa884" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_8cdeb90e-0650-404a-a708-6cc5d76d7c09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_d0587ee0-170d-410e-bd67-8d8eb4f8eb23" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_8cdeb90e-0650-404a-a708-6cc5d76d7c09" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_41c4f604-7da2-439f-a24a-7751cf75acff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_d0587ee0-170d-410e-bd67-8d8eb4f8eb23" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_41c4f604-7da2-439f-a24a-7751cf75acff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear_82c5621f-ba0b-4b59-90aa-b2d298194f56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_d0587ee0-170d-410e-bd67-8d8eb4f8eb23" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear_82c5621f-ba0b-4b59-90aa-b2d298194f56" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/DebtScheduleofCarryingAmountsDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#DebtScheduleofCarryingAmountsDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/DebtScheduleofCarryingAmountsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_cfbc3035-290c-4612-a8ad-8321ea998ab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_c0e1865c-8c18-43b2-97cf-967405d52f43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_cfbc3035-290c-4612-a8ad-8321ea998ab4" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_c0e1865c-8c18-43b2-97cf-967405d52f43" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_0668d233-0554-4994-b842-a125466f419a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_cfbc3035-290c-4612-a8ad-8321ea998ab4" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_0668d233-0554-4994-b842-a125466f419a" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/DebtScheduleofInterestExpenseDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#DebtScheduleofInterestExpenseDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/DebtScheduleofInterestExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_fd621af0-9fbd-4640-866d-2bbde66ff359" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_AmortizationOfDebtExitFees_62af20af-239a-48f3-944a-63b610212e72" xlink:href="sncr-20250630.xsd#sncr_AmortizationOfDebtExitFees"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseNonoperating_fd621af0-9fbd-4640-866d-2bbde66ff359" xlink:to="loc_sncr_AmortizationOfDebtExitFees_62af20af-239a-48f3-944a-63b610212e72" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOther_b0b311b4-2e4b-4b53-ae2b-7de528c67546" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseOther"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseNonoperating_fd621af0-9fbd-4640-866d-2bbde66ff359" xlink:to="loc_us-gaap_InterestExpenseOther_b0b311b4-2e4b-4b53-ae2b-7de528c67546" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_706c6651-aba9-445c-8e96-b8a3adc173a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseNonoperating_fd621af0-9fbd-4640-866d-2bbde66ff359" xlink:to="loc_us-gaap_InterestExpenseDebt_706c6651-aba9-445c-8e96-b8a3adc173a4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_4bba1f1d-5e97-47f5-86c0-56b2c6fb1d6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseNonoperating_fd621af0-9fbd-4640-866d-2bbde66ff359" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_4bba1f1d-5e97-47f5-86c0-56b2c6fb1d6f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/EarningsperCommonShareEPSDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#EarningsperCommonShareEPSDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/EarningsperCommonShareEPSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_54b61201-badd-4db4-ad75-b963a93b5bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_09fe673f-b4d9-4c71-bf28-4dde7ab4f85b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_54b61201-badd-4db4-ad75-b963a93b5bdd" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_09fe673f-b4d9-4c71-bf28-4dde7ab4f85b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_83c6b60c-e6af-4b37-b4df-a1cb8e10f188" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_524d9615-ef35-4ef2-8a78-cc6c3cc4f9ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_83c6b60c-e6af-4b37-b4df-a1cb8e10f188" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_524d9615-ef35-4ef2-8a78-cc6c3cc4f9ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_sncr_PreferredStockDividend_57fa6b6a-86af-4ea8-8f8f-cc00c26b1892" xlink:href="sncr-20250630.xsd#sncr_PreferredStockDividend"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_83c6b60c-e6af-4b37-b4df-a1cb8e10f188" xlink:to="loc_sncr_PreferredStockDividend_57fa6b6a-86af-4ea8-8f8f-cc00c26b1892" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_ffd9b0c9-70b4-477e-92c8-c69b427ab256" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_83c6b60c-e6af-4b37-b4df-a1cb8e10f188" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_ffd9b0c9-70b4-477e-92c8-c69b427ab256" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://synchronoss.com/role/CommitmentsDetails" xlink:type="simple" xlink:href="sncr-20250630.xsd#CommitmentsDetails"/>
  <link:calculationLink xlink:role="http://synchronoss.com/role/CommitmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PurchaseObligation_520a2066-5f75-42ec-9a55-7dcf43aa4511" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PurchaseObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PurchaseObligationDueInThirdYear_f55119e3-92ff-46fb-a9a5-5daddb739528" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PurchaseObligationDueInThirdYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PurchaseObligation_520a2066-5f75-42ec-9a55-7dcf43aa4511" xlink:to="loc_us-gaap_PurchaseObligationDueInThirdYear_f55119e3-92ff-46fb-a9a5-5daddb739528" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear_4f91d3ec-1e40-4595-b06a-e3b35d48c30c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PurchaseObligation_520a2066-5f75-42ec-9a55-7dcf43aa4511" xlink:to="loc_us-gaap_PurchaseObligationFutureMinimumPaymentsRemainderOfFiscalYear_4f91d3ec-1e40-4595-b06a-e3b35d48c30c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PurchaseObligationDueInSecondYear_4dedd67e-f730-4272-b9d9-3dd6d9c81dcc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PurchaseObligationDueInSecondYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PurchaseObligation_520a2066-5f75-42ec-9a55-7dcf43aa4511" xlink:to="loc_us-gaap_PurchaseObligationDueInSecondYear_4dedd67e-f730-4272-b9d9-3dd6d9c81dcc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PurchaseObligationDueInNextTwelveMonths_3ef7c931-0037-419b-9291-63d4b8e2b052" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PurchaseObligationDueInNextTwelveMonths"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_PurchaseObligation_520a2066-5f75-42ec-9a55-7dcf43aa4511" xlink:to="loc_us-gaap_PurchaseObligationDueInNextTwelveMonths_3ef7c931-0037-419b-9291-63d4b8e2b052" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
