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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e6509-5a4e-7d30-a715-c099fbc23347,g:f628befb-692d-4577-8d6c-cc913dcec0a8-->
<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:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="gpmt-20260630.xsd#CONDENSEDCONSOLIDATEDBALANCESHEETS"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseRepurchaseLiability_019e6509-5ebb-7dae-9c94-04f91d9e6024" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsSoldUnderAgreementsToRepurchaseRepurchaseLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:to="loc_us-gaap_AssetsSoldUnderAgreementsToRepurchaseRepurchaseLiability_019e6509-5ebb-7dae-9c94-04f91d9e6024" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BeneficialInterest_019e6509-5ebb-7db6-947c-e8f892d6dfb7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BeneficialInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:to="loc_us-gaap_BeneficialInterest_019e6509-5ebb-7db6-947c-e8f892d6dfb7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherSecuredFinancings_019e6509-5ebb-796b-b487-fcd0b3efe950" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherSecuredFinancings"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:to="loc_us-gaap_OtherSecuredFinancings_019e6509-5ebb-796b-b487-fcd0b3efe950" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebt_019e6509-5ebb-7425-927b-3b864b2e45e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebt"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:to="loc_us-gaap_SecuredDebt_019e6509-5ebb-7425-927b-3b864b2e45e9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_019e6509-5ebb-7174-89ac-b488022c4621" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPayableCurrentAndNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:to="loc_us-gaap_DividendsPayableCurrentAndNoncurrent_019e6509-5ebb-7174-89ac-b488022c4621" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_RealEstateOwnedLiabilitiesHeldForSale_019f1d5d-0d42-751d-b065-d4d278f0ff72" xlink:href="gpmt-20260630.xsd#gpmt_RealEstateOwnedLiabilitiesHeldForSale"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:to="loc_gpmt_RealEstateOwnedLiabilitiesHeldForSale_019f1d5d-0d42-751d-b065-d4d278f0ff72" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_019f1d5d-0d42-73d7-924a-7c6e378e4579" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilities"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019e6509-5ebb-77a6-8803-aa2248768721" xlink:to="loc_us-gaap_OtherLiabilities_019f1d5d-0d42-73d7-924a-7c6e378e4579" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5ebb-7538-9e8b-c65331d5782b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019e6509-5ebb-79c1-983b-2e3e90023fe6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5ebb-7538-9e8b-c65331d5782b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019e6509-5ebb-79c1-983b-2e3e90023fe6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019e6509-5ebb-7345-8df4-eecc3039cf25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5ebb-7538-9e8b-c65331d5782b" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019e6509-5ebb-7345-8df4-eecc3039cf25" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019e6509-5ebb-7981-b787-4883ef4939bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e6509-5ebb-7735-bf3a-f309d07710a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019e6509-5ebb-7981-b787-4883ef4939bb" xlink:to="loc_us-gaap_StockholdersEquity_019e6509-5ebb-7735-bf3a-f309d07710a3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_019e6509-5ebb-751f-935f-e07977f34bfa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019e6509-5ebb-7981-b787-4883ef4939bb" xlink:to="loc_us-gaap_MinorityInterest_019e6509-5ebb-751f-935f-e07977f34bfa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5ebb-7f30-adf1-5e362275f167" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5ebb-7f30-adf1-5e362275f167" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e6509-5ebb-7cf7-a54e-58c8c159d937" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e6509-5ebb-7cf7-a54e-58c8c159d937" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_019e6509-5ebb-7c3e-9c7f-900190f1412f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCash"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:to="loc_us-gaap_RestrictedCash_019e6509-5ebb-7c3e-9c7f-900190f1412f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateInvestments_019e6509-5ebb-7c7d-be8b-e39d7024324d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealEstateInvestments"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:to="loc_us-gaap_RealEstateInvestments_019e6509-5ebb-7c7d-be8b-e39d7024324d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateHeldforsale_019e6509-5ebb-7416-925e-4aaba41a2aae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealEstateHeldforsale"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:to="loc_us-gaap_RealEstateHeldforsale_019e6509-5ebb-7416-925e-4aaba41a2aae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestReceivable_019e6509-5ebb-7d32-b54d-1d0641c085dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestReceivable"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:to="loc_us-gaap_InterestReceivable_019e6509-5ebb-7d32-b54d-1d0641c085dd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets_019ef7f0-3075-73d7-b19c-d529f219e3b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssets"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019e6509-5ebb-7b6a-95a7-fb3cf1ea09fa" xlink:to="loc_us-gaap_OtherAssets_019ef7f0-3075-73d7-b19c-d529f219e3b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e6509-5ebb-75df-a5d8-d0cbf00d4e84" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019e6509-5ebb-7d9f-9126-7da700346247" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6509-5ebb-75df-a5d8-d0cbf00d4e84" xlink:to="loc_us-gaap_PreferredStockValue_019e6509-5ebb-7d9f-9126-7da700346247" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019e6509-5ebb-7dcf-89fc-c6c09919d64c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6509-5ebb-75df-a5d8-d0cbf00d4e84" xlink:to="loc_us-gaap_CommonStockValue_019e6509-5ebb-7dcf-89fc-c6c09919d64c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_019e6509-5ebb-700c-be70-98ddd2ff15f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6509-5ebb-75df-a5d8-d0cbf00d4e84" xlink:to="loc_us-gaap_AdditionalPaidInCapital_019e6509-5ebb-700c-be70-98ddd2ff15f7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CumulativeEarningsDeficit_019e6509-5ebb-70a9-8b61-ea9a76d56a25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CumulativeEarningsDeficit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6509-5ebb-75df-a5d8-d0cbf00d4e84" xlink:to="loc_us-gaap_CumulativeEarningsDeficit_019e6509-5ebb-70a9-8b61-ea9a76d56a25" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CumulativeDividends_019e6509-5ebb-7e45-bd2e-aa68b6524574" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CumulativeDividends"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019e6509-5ebb-75df-a5d8-d0cbf00d4e84" xlink:to="loc_us-gaap_CumulativeDividends_019e6509-5ebb-7e45-bd2e-aa68b6524574" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6509-5ebb-7484-8a38-02199b877f6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019e6509-5ebb-7179-8e21-52e796c86fcb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6509-5ebb-7484-8a38-02199b877f6b" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019e6509-5ebb-7179-8e21-52e796c86fcb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019e6509-5ebb-7c60-8b02-b3cc77f245ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6509-5ebb-7484-8a38-02199b877f6b" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019e6509-5ebb-7c60-8b02-b3cc77f245ea" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019e6509-5ebb-7ce1-b1c2-b3622dc96f3b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019e6509-5ebb-7484-8a38-02199b877f6b" xlink:to="loc_us-gaap_Liabilities_019e6509-5ebb-7ce1-b1c2-b3622dc96f3b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVELOSSINCOME" xlink:type="simple" xlink:href="gpmt-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVELOSSINCOME"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVELOSSINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_019e6509-5ebb-7058-beb5-df4dd12a4334" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepurchaseAgreementsInterestExpenseAmount_019e6509-5ebb-7f4d-8e3c-a11fd4e51519" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepurchaseAgreementsInterestExpenseAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_019e6509-5ebb-7058-beb5-df4dd12a4334" xlink:to="loc_us-gaap_RepurchaseAgreementsInterestExpenseAmount_019e6509-5ebb-7f4d-8e3c-a11fd4e51519" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseBeneficialInterestsIssuedByConsolidatedVariableInterestEntities_019e6509-5ebb-7b76-9635-85a8a01cb11a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseBeneficialInterestsIssuedByConsolidatedVariableInterestEntities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_019e6509-5ebb-7058-beb5-df4dd12a4334" xlink:to="loc_us-gaap_InterestExpenseBeneficialInterestsIssuedByConsolidatedVariableInterestEntities_019e6509-5ebb-7b76-9635-85a8a01cb11a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_InterestExpenseOtherSecuredFinancings_019e6509-5ebb-7176-a6ef-14c0ed5df4e2" xlink:href="gpmt-20260630.xsd#gpmt_InterestExpenseOtherSecuredFinancings"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_019e6509-5ebb-7058-beb5-df4dd12a4334" xlink:to="loc_gpmt_InterestExpenseOtherSecuredFinancings_019e6509-5ebb-7176-a6ef-14c0ed5df4e2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_InterestExpenseMortgageLoan_019e6509-5ebb-795d-8e03-e19df542faee" xlink:href="gpmt-20260630.xsd#gpmt_InterestExpenseMortgageLoan"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_019e6509-5ebb-7058-beb5-df4dd12a4334" xlink:to="loc_gpmt_InterestExpenseMortgageLoan_019e6509-5ebb-795d-8e03-e19df542faee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_InterestExpenseLoanParticipationsSold_019f1d07-5ebf-7af8-b8b1-4b6848ca55ad" xlink:href="gpmt-20260630.xsd#gpmt_InterestExpenseLoanParticipationsSold"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_019e6509-5ebb-7058-beb5-df4dd12a4334" xlink:to="loc_gpmt_InterestExpenseLoanParticipationsSold_019f1d07-5ebf-7af8-b8b1-4b6848ca55ad" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019e6509-5ebb-74a6-a934-5a700502d773" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_RealEstateOwnedPropertyOperatingRevenue_019e6509-5ebb-784e-bcf9-f22c99ff70ca" xlink:href="gpmt-20260630.xsd#gpmt_RealEstateOwnedPropertyOperatingRevenue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019e6509-5ebb-74a6-a934-5a700502d773" xlink:to="loc_gpmt_RealEstateOwnedPropertyOperatingRevenue_019e6509-5ebb-784e-bcf9-f22c99ff70ca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_AccountsandFinancingReceivableCreditLossExpenseReversal_019e6509-5ebb-77e8-be1c-8d63c540bfc9" xlink:href="gpmt-20260630.xsd#gpmt_AccountsandFinancingReceivableCreditLossExpenseReversal"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019e6509-5ebb-74a6-a934-5a700502d773" xlink:to="loc_gpmt_AccountsandFinancingReceivableCreditLossExpenseReversal_019e6509-5ebb-77e8-be1c-8d63c540bfc9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnSalesOfInvestmentRealEstate_019e736a-2013-7035-871d-444d35e2c3ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainsLossesOnSalesOfInvestmentRealEstate"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019e6509-5ebb-74a6-a934-5a700502d773" xlink:to="loc_us-gaap_GainsLossesOnSalesOfInvestmentRealEstate_019e736a-2013-7035-871d-444d35e2c3ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSalesOfLoansNet_019e6509-5ebb-734e-b4e5-4940d58f5026" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSalesOfLoansNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019e6509-5ebb-74a6-a934-5a700502d773" xlink:to="loc_us-gaap_GainLossOnSalesOfLoansNet_019e6509-5ebb-734e-b4e5-4940d58f5026" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019e6509-5ebb-7f58-ad11-4e50c88eb9d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-75aa-b01d-6a34a325a658" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019e6509-5ebb-7f58-ad11-4e50c88eb9d3" xlink:to="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-75aa-b01d-6a34a325a658" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019e6509-5ebb-7657-bb1b-9eca2dcfbe22" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019e6509-5ebb-7f58-ad11-4e50c88eb9d3" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019e6509-5ebb-7657-bb1b-9eca2dcfbe22" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e6509-5ebb-7af5-983c-31dd2d009902" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019e6509-5ebb-78c7-9a54-598dc6be11be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019e6509-5ebb-7af5-983c-31dd2d009902" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019e6509-5ebb-78c7-9a54-598dc6be11be" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRevenueExpenseNet_019e6509-5ebb-70b9-b634-bf2483f0093c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRevenueExpenseNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_019e6509-5ebb-78dc-a185-8df4eafac01d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestRevenueExpenseNet_019e6509-5ebb-70b9-b634-bf2483f0093c" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_019e6509-5ebb-78dc-a185-8df4eafac01d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_019e6509-5ebb-72ea-9c2d-1868d0d857f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpense"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestRevenueExpenseNet_019e6509-5ebb-70b9-b634-bf2483f0093c" xlink:to="loc_us-gaap_InterestExpense_019e6509-5ebb-72ea-9c2d-1868d0d857f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6509-5ebb-7990-936c-f030d9400922" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-7fa4-9fd2-a21d7aab8e0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpenses"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6509-5ebb-7990-936c-f030d9400922" xlink:to="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-7fa4-9fd2-a21d7aab8e0f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019e6509-5ebb-7bc8-8775-61aaa3b02488" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6509-5ebb-7990-936c-f030d9400922" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019e6509-5ebb-7bc8-8775-61aaa3b02488" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRevenueExpenseNet_019e6509-5ebb-743c-8a6e-7e562193cb12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRevenueExpenseNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6509-5ebb-7990-936c-f030d9400922" xlink:to="loc_us-gaap_InterestRevenueExpenseNet_019e6509-5ebb-743c-8a6e-7e562193cb12" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_019e6509-5ebb-7f32-a476-f45946f2abc3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDomesticDeposits_019e6509-5ebb-7943-8180-61c3e6615499" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeDomesticDeposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019e6509-5ebb-7f32-a476-f45946f2abc3" xlink:to="loc_us-gaap_InterestIncomeDomesticDeposits_019e6509-5ebb-7943-8180-61c3e6615499" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansCommercialRealEstate_019e6509-5ebb-723b-8799-ce03959055aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndFeeIncomeLoansCommercialRealEstate"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019e6509-5ebb-7f32-a476-f45946f2abc3" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansCommercialRealEstate_019e6509-5ebb-723b-8799-ce03959055aa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-79d2-bd82-8c91251787e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019e6509-5ebb-7e26-80ef-de99d312a65f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-79d2-bd82-8c91251787e1" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019e6509-5ebb-7e26-80ef-de99d312a65f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_ServicingExpense_019e6509-5ebb-7e23-bbdf-cb5bd260b572" xlink:href="gpmt-20260630.xsd#gpmt_ServicingExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-79d2-bd82-8c91251787e1" xlink:to="loc_gpmt_ServicingExpense_019e6509-5ebb-7e23-bbdf-cb5bd260b572" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfRealEstate_019e6509-5ebb-76a0-b99f-595804ac07e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfRealEstate"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-79d2-bd82-8c91251787e1" xlink:to="loc_us-gaap_ImpairmentOfRealEstate_019e6509-5ebb-76a0-b99f-595804ac07e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_RealEstateOwnedOperatingCostsAndExpenses_019e6509-5ebb-74a8-87ab-ffb1507db4e3" xlink:href="gpmt-20260630.xsd#gpmt_RealEstateOwnedOperatingCostsAndExpenses"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-79d2-bd82-8c91251787e1" xlink:to="loc_gpmt_RealEstateOwnedOperatingCostsAndExpenses_019e6509-5ebb-74a8-87ab-ffb1507db4e3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostAndExpenseOperating_019f1d07-fa22-778a-b878-01352549ac0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCostAndExpenseOperating"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019e6509-5ebb-79d2-bd82-8c91251787e1" xlink:to="loc_us-gaap_OtherCostAndExpenseOperating_019f1d07-fa22-778a-b878-01352549ac0f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-7152-95a1-3867a526c976" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6509-5ebb-771e-bf3a-af668292d6c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-7152-95a1-3867a526c976" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019e6509-5ebb-771e-bf3a-af668292d6c4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019e6509-5ebb-7c00-9065-4e16ae993258" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-7152-95a1-3867a526c976" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019e6509-5ebb-7c00-9065-4e16ae993258" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019e6509-5ebb-7259-ac71-cfdb1a42ff6a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-7166-8e49-ddba1590140b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019e6509-5ebb-7259-ac71-cfdb1a42ff6a" xlink:to="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-7166-8e49-ddba1590140b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019e6509-5ebb-74cc-b306-a3a199406252" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019e6509-5ebb-7259-ac71-cfdb1a42ff6a" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019e6509-5ebb-74cc-b306-a3a199406252" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="gpmt-20260630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_ProceedsfromAssetsSoldunderAgreementstoRepurchase_019e6509-5ebb-7ed7-b052-207bb295b2df" xlink:href="gpmt-20260630.xsd#gpmt_ProceedsfromAssetsSoldunderAgreementstoRepurchase"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_gpmt_ProceedsfromAssetsSoldunderAgreementstoRepurchase_019e6509-5ebb-7ed7-b052-207bb295b2df" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_PrincipalPaymentsonAssetsSoldunderAgreementstoRepurchase_019e6509-5ebb-7aaf-b307-7b6b820ec094" xlink:href="gpmt-20260630.xsd#gpmt_PrincipalPaymentsonAssetsSoldunderAgreementstoRepurchase"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_gpmt_PrincipalPaymentsonAssetsSoldunderAgreementstoRepurchase_019e6509-5ebb-7aaf-b307-7b6b820ec094" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfAccountsReceivableSecuritization_019e6509-5ebb-7710-85ed-24789a240872" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfAccountsReceivableSecuritization"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_us-gaap_RepaymentsOfAccountsReceivableSecuritization_019e6509-5ebb-7710-85ed-24789a240872" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_ProceedsFromLoanParticipationsSold_019e73a9-453b-7395-9a3f-6c50c6d28aa0" xlink:href="gpmt-20260630.xsd#gpmt_ProceedsFromLoanParticipationsSold"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_gpmt_ProceedsFromLoanParticipationsSold_019e73a9-453b-7395-9a3f-6c50c6d28aa0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019e6509-5ebb-7353-8c1b-f24b40ef58e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_019e6509-5ebb-7353-8c1b-f24b40ef58e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_019e6509-5ebb-771d-9105-73554e018a25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_019e6509-5ebb-771d-9105-73554e018a25" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019e6509-5ebb-78e3-a54d-f49acf39e086" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019e6509-5ebb-78e3-a54d-f49acf39e086" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_019e73a7-8a69-7570-b4cd-07d3d4cf11ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_019e73a7-8a69-7570-b4cd-07d3d4cf11ab" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_019f2257-a302-7b5b-a31b-2a71e769ab28" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-7518-abc0-c45c530f5329" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_019f2257-a302-7b5b-a31b-2a71e769ab28" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-7b97-863e-5c1ed1032990" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_NetIncomeLoss_019e6509-5ebb-7b97-863e-5c1ed1032990" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019e6509-5ebb-7858-9915-f31d0f08939d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019e6509-5ebb-7858-9915-f31d0f08939d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_019e6509-5ebb-7f3c-beb3-29a6951fe69c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_019e6509-5ebb-7f3c-beb3-29a6951fe69c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_AccountsandFinancingReceivableCreditLossExpenseReversal_019e6509-5ebb-79e5-982d-ca2a160c3c69" xlink:href="gpmt-20260630.xsd#gpmt_AccountsandFinancingReceivableCreditLossExpenseReversal"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_gpmt_AccountsandFinancingReceivableCreditLossExpenseReversal_019e6509-5ebb-79e5-982d-ca2a160c3c69" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfRealEstate_019e6509-5ebb-7da6-8ead-c802a4696d22" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ImpairmentOfRealEstate"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_ImpairmentOfRealEstate_019e6509-5ebb-7da6-8ead-c802a4696d22" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSalesOfLoansNet_019e6509-5ebb-786e-a3d1-960e10f3f52d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSalesOfLoansNet"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_GainLossOnSalesOfLoansNet_019e6509-5ebb-786e-a3d1-960e10f3f52d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019e6509-5ebb-729c-98c5-7e7be25eb517" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_ShareBasedCompensation_019e6509-5ebb-729c-98c5-7e7be25eb517" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019e6509-5ebb-7bf6-9081-f24dc1753a5e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019e6509-5ebb-7bf6-9081-f24dc1753a5e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StraightLineRent_019e6509-5ebb-78f8-8000-bf43abfcb845" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StraightLineRent"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_StraightLineRent_019e6509-5ebb-78f8-8000-bf43abfcb845" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnSalesOfInvestmentRealEstate_019e6509-5ebb-7031-a255-9b8ce0fa1270" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainsLossesOnSalesOfInvestmentRealEstate"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_GainsLossesOnSalesOfInvestmentRealEstate_019e6509-5ebb-7031-a255-9b8ce0fa1270" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_019e739f-4993-7c9f-a595-00716b2c7e80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_019e739f-4993-7c9f-a595-00716b2c7e80" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_019e6509-5ebb-706c-9a57-c25d28b248f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_019e6509-5ebb-706c-9a57-c25d28b248f8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_019f1d09-504c-740e-a04a-d1d0f0b724e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-7527-b816-9fc0cb417565" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingLiabilities_019f1d09-504c-740e-a04a-d1d0f0b724e2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e6509-5ebb-7700-9ea4-ef5d3f5fbacc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-742e-98ff-d83890deb13b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e6509-5ebb-7700-9ea4-ef5d3f5fbacc" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019e6509-5ebb-742e-98ff-d83890deb13b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-7b8a-a995-b862ad67b077" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e6509-5ebb-7700-9ea4-ef5d3f5fbacc" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-7b8a-a995-b862ad67b077" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-799a-b2fb-77b5ba68f87f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019e6509-5ebb-7700-9ea4-ef5d3f5fbacc" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019e6509-5ebb-799a-b2fb-77b5ba68f87f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireLoansAndLeasesHeldForInvestment_019e6509-5ebb-74d3-a809-1721f9694401" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireLoansAndLeasesHeldForInvestment"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:to="loc_us-gaap_PaymentsToAcquireLoansAndLeasesHeldForInvestment_019e6509-5ebb-74d3-a809-1721f9694401" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfLoansHeldForInvestment_019e6509-5ebb-7227-9a24-cc0aae2cb910" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfLoansHeldForInvestment"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:to="loc_us-gaap_ProceedsFromSaleOfLoansHeldForInvestment_019e6509-5ebb-7227-9a24-cc0aae2cb910" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPrincipalRepaymentsOnLoansAndLeasesHeldForInvestment_019e6509-5ebb-764a-a87d-e265142abbe5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromPrincipalRepaymentsOnLoansAndLeasesHeldForInvestment"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:to="loc_us-gaap_ProceedsFromPrincipalRepaymentsOnLoansAndLeasesHeldForInvestment_019e6509-5ebb-764a-a87d-e265142abbe5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment_019e6509-5ebb-729c-8ea3-94c6ae82258c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireRealEstateHeldForInvestment"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:to="loc_us-gaap_PaymentsToAcquireRealEstateHeldForInvestment_019e6509-5ebb-729c-8ea3-94c6ae82258c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment_019e73a5-c15d-7978-8765-73a2fefc4d93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:to="loc_us-gaap_ProceedsFromSaleOfRealEstateHeldforinvestment_019e73a5-c15d-7978-8765-73a2fefc4d93" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_PaymentForAcquisitionCostsRealEstateHeldForInvestment_019e6509-5ebb-7c9c-a781-d84155bd928d" xlink:href="gpmt-20260630.xsd#gpmt_PaymentForAcquisitionCostsRealEstateHeldForInvestment"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:to="loc_gpmt_PaymentForAcquisitionCostsRealEstateHeldForInvestment_019e6509-5ebb-7c9c-a781-d84155bd928d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireOtherInvestments_019e6509-5ebb-7723-b4e1-feed2f918769" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireOtherInvestments"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019e6509-5ebb-78d4-816e-7f4a51cb02ed" xlink:to="loc_us-gaap_PaymentsToAcquireOtherInvestments_019e6509-5ebb-7723-b4e1-feed2f918769" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofLoansHeldforInvestmentDetails" xlink:type="simple" xlink:href="gpmt-20260630.xsd#LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofLoansHeldforInvestmentDetails"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofLoansHeldforInvestmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-79d8-a41b-9afc33f3529a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_FinancingReceivableBeforeAllowanceForCreditLossUnpaidPrincipalBalance_019e6509-5f8f-7dd2-b9fb-dc0a75d880d5" xlink:href="gpmt-20260630.xsd#gpmt_FinancingReceivableBeforeAllowanceForCreditLossUnpaidPrincipalBalance"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-79d8-a41b-9afc33f3529a" xlink:to="loc_gpmt_FinancingReceivableBeforeAllowanceForCreditLossUnpaidPrincipalBalance_019e6509-5f8f-7dd2-b9fb-dc0a75d880d5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019e6509-5f8f-7ed5-8b94-c0d957802ab6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-79d8-a41b-9afc33f3529a" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019e6509-5f8f-7ed5-8b94-c0d957802ab6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_UnamortizedNetDeferredOriginationFeesLoansHeldforInvestment_019e6509-5f8f-7713-9ded-bef8c3cbea50" xlink:href="gpmt-20260630.xsd#gpmt_UnamortizedNetDeferredOriginationFeesLoansHeldforInvestment"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-79d8-a41b-9afc33f3529a" xlink:to="loc_gpmt_UnamortizedNetDeferredOriginationFeesLoansHeldforInvestment_019e6509-5f8f-7713-9ded-bef8c3cbea50" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofAllowanceforCreditLossesDetails" xlink:type="simple" xlink:href="gpmt-20260630.xsd#LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofAllowanceforCreditLossesDetails"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofAllowanceforCreditLossesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityWriteoff_019e6509-5f8f-7b34-9f7e-01c266ba5421" xlink:href="gpmt-20260630.xsd#gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityWriteoff"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019e6509-5f8f-7f53-acec-ccf930a9ebcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityWriteoff_019e6509-5f8f-7b34-9f7e-01c266ba5421" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019e6509-5f8f-7f53-acec-ccf930a9ebcc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_OffBalanceSheetCreditLossLiabilityWriteoff_019e6509-5f8f-7738-869b-f2d035843b7c" xlink:href="gpmt-20260630.xsd#gpmt_OffBalanceSheetCreditLossLiabilityWriteoff"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityWriteoff_019e6509-5f8f-7b34-9f7e-01c266ba5421" xlink:to="loc_gpmt_OffBalanceSheetCreditLossLiabilityWriteoff_019e6509-5f8f-7738-869b-f2d035843b7c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_FinancingReceivableExcludingAccruedInterestAndOffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal_019e6509-5f8f-7fe7-9da8-15ff10888aae" xlink:href="gpmt-20260630.xsd#gpmt_FinancingReceivableExcludingAccruedInterestAndOffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_019e6509-5f8f-7ecf-beee-670532010d76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableExcludingAccruedInterestAndOffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal_019e6509-5f8f-7fe7-9da8-15ff10888aae" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_019e6509-5f8f-7ecf-beee-670532010d76" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal_019e6509-5f8f-7d9b-b985-86f68326e784" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableExcludingAccruedInterestAndOffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal_019e6509-5f8f-7fe7-9da8-15ff10888aae" xlink:to="loc_us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal_019e6509-5f8f-7d9b-b985-86f68326e784" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterestAndOffBalanceSheetCreditLossLiability_019e6509-5f8f-7e88-9cb0-40c0cb0c9480" xlink:href="gpmt-20260630.xsd#gpmt_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterestAndOffBalanceSheetCreditLossLiability"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019e6509-5f8f-7cbc-9e9c-6118861e8e87" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterestAndOffBalanceSheetCreditLossLiability_019e6509-5f8f-7e88-9cb0-40c0cb0c9480" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019e6509-5f8f-7cbc-9e9c-6118861e8e87" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OffBalanceSheetCreditLossLiability_019e6509-5f8f-7027-9d25-23ffb60f5900" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OffBalanceSheetCreditLossLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterestAndOffBalanceSheetCreditLossLiability_019e6509-5f8f-7e88-9cb0-40c0cb0c9480" xlink:to="loc_us-gaap_OffBalanceSheetCreditLossLiability_019e6509-5f8f-7027-9d25-23ffb60f5900" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityRecovery_019e6509-5f8f-79d2-8a0a-ddac1e5efbd6" xlink:href="gpmt-20260630.xsd#gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityRecovery"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_019e6509-5f8f-75f6-9aa4-33078af500b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityRecovery_019e6509-5f8f-79d2-8a0a-ddac1e5efbd6" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_019e6509-5f8f-75f6-9aa4-33078af500b6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_OffBalanceSheetCreditLossLiabilityRecovery_019e6509-5f8f-76ea-ac1a-23034b8f3e79" xlink:href="gpmt-20260630.xsd#gpmt_OffBalanceSheetCreditLossLiabilityRecovery"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossAndOffBalanceSheetCreditLossLiabilityRecovery_019e6509-5f8f-79d2-8a0a-ddac1e5efbd6" xlink:to="loc_gpmt_OffBalanceSheetCreditLossLiabilityRecovery_019e6509-5f8f-76ea-ac1a-23034b8f3e79" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofLoansHeldforInvestmentbyInternalRiskRatingDetails" xlink:type="simple" xlink:href="gpmt-20260630.xsd#LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofLoansHeldforInvestmentbyInternalRiskRatingDetails"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/LoansHeldforInvestmentNetofAllowanceforCreditLossesScheduleofLoansHeldforInvestmentbyInternalRiskRatingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019e6509-5f8f-704a-8bdf-ecdd25880a34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanSixYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-70e4-b455-ef6de246806a" xlink:href="gpmt-20260630.xsd#gpmt_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanSixYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019e6509-5f8f-704a-8bdf-ecdd25880a34" xlink:to="loc_gpmt_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanSixYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-70e4-b455-ef6de246806a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-7bcd-a7a2-98dc0163e696" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019e6509-5f8f-704a-8bdf-ecdd25880a34" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-7bcd-a7a2-98dc0163e696" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_019e6509-5f8f-7e90-ac35-4ae4cb838058" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019e6509-5f8f-704a-8bdf-ecdd25880a34" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_019e6509-5f8f-7e90-ac35-4ae4cb838058" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-7301-a0b3-2fb3e473cde1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019e6509-5f8f-704a-8bdf-ecdd25880a34" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-7301-a0b3-2fb3e473cde1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-7c3e-a082-5a82e5e9882d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019e6509-5f8f-704a-8bdf-ecdd25880a34" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-7c3e-a082-5a82e5e9882d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-76f8-9fb4-4be9b4cf7a8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019e6509-5f8f-704a-8bdf-ecdd25880a34" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_019e6509-5f8f-76f8-9fb4-4be9b4cf7a8b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-714b-b53a-274f25ef8eee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_019e6509-5f8f-7881-bb36-4cd795fc3aea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-714b-b53a-274f25ef8eee" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_019e6509-5f8f-7881-bb36-4cd795fc3aea" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_019e6509-5f8f-7ffb-ae48-794a34300bb9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-714b-b53a-274f25ef8eee" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_019e6509-5f8f-7ffb-ae48-794a34300bb9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_019e6509-5f8f-709c-838b-b986bcec81f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-714b-b53a-274f25ef8eee" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_019e6509-5f8f-709c-838b-b986bcec81f3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_019e6509-5f8f-761e-bd66-a65b7a610797" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-714b-b53a-274f25ef8eee" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_019e6509-5f8f-761e-bd66-a65b7a610797" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_019e6509-5f8f-77fb-a78d-e1a89f0480b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-714b-b53a-274f25ef8eee" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_019e6509-5f8f-77fb-a78d-e1a89f0480b4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_019e6509-5f8f-7dac-89d3-78c4a4864791" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019e6509-5f8f-714b-b53a-274f25ef8eee" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_019e6509-5f8f-7dac-89d3-78c4a4864791" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/RealEstateOwnedScheduleofRealEstateAcquiredThroughForeclosureFinancialStatementsDisclosureDetails" xlink:type="simple" xlink:href="gpmt-20260630.xsd#RealEstateOwnedScheduleofRealEstateAcquiredThroughForeclosureFinancialStatementsDisclosureDetails"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/RealEstateOwnedScheduleofRealEstateAcquiredThroughForeclosureFinancialStatementsDisclosureDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNet_019e6509-5f8f-7069-af5d-2dbabf8bcfda" xlink:href="gpmt-20260630.xsd#gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssets_019e6509-5f8f-77a1-910f-919c10035972" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssets"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNet_019e6509-5f8f-7069-af5d-2dbabf8bcfda" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationIntangibleAssets_019e6509-5f8f-77a1-910f-919c10035972" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsAccumulatedDepreciation_019e6509-5f8f-789c-ace6-b32889673dda" xlink:href="gpmt-20260630.xsd#gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsAccumulatedDepreciation"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsNet_019e6509-5f8f-7069-af5d-2dbabf8bcfda" xlink:to="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsAccumulatedDepreciation_019e6509-5f8f-789c-ace6-b32889673dda" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_019e6509-5f8f-7038-8ca2-9d74efd020f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleRealEstateLiabilities_019e6509-5f8f-770b-9733-787c0f0a4e68" xlink:href="gpmt-20260630.xsd#gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleRealEstateLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_019e6509-5f8f-7038-8ca2-9d74efd020f7" xlink:to="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationIntangibleRealEstateLiabilities_019e6509-5f8f-770b-9733-787c0f0a4e68" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationLeaseLiability_019e6509-5f8f-7580-8078-09facf35ba24" xlink:href="gpmt-20260630.xsd#gpmt_DisposalGroupIncludingDiscontinuedOperationLeaseLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_019e6509-5f8f-7038-8ca2-9d74efd020f7" xlink:to="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationLeaseLiability_019e6509-5f8f-7580-8078-09facf35ba24" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationAccumulatedDepreciationLiabilities_019e6509-5f8f-7da2-b2ac-6f47e9c3584b" xlink:href="gpmt-20260630.xsd#gpmt_DisposalGroupIncludingDiscontinuedOperationAccumulatedDepreciationLiabilities"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_019e6509-5f8f-7038-8ca2-9d74efd020f7" xlink:to="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationAccumulatedDepreciationLiabilities_019e6509-5f8f-7da2-b2ac-6f47e9c3584b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNet_019e6509-5f8f-7572-949d-396b99885fdb" xlink:href="gpmt-20260630.xsd#gpmt_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment_019e6509-5f8f-7f0c-935b-7f085a473d70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNet_019e6509-5f8f-7572-949d-396b99885fdb" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment_019e6509-5f8f-7f0c-935b-7f085a473d70" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationAccumulatedDepreciation_019e6509-5f8f-7fc8-afca-c45db72aad6c" xlink:href="gpmt-20260630.xsd#gpmt_DisposalGroupIncludingDiscontinuedOperationAccumulatedDepreciation"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNet_019e6509-5f8f-7572-949d-396b99885fdb" xlink:to="loc_gpmt_DisposalGroupIncludingDiscontinuedOperationAccumulatedDepreciation_019e6509-5f8f-7fc8-afca-c45db72aad6c" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/RealEstateOwnedScheduleofIncomeLossfromRealEstateOwnedDetails" xlink:type="simple" xlink:href="gpmt-20260630.xsd#RealEstateOwnedScheduleofIncomeLossfromRealEstateOwnedDetails"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/RealEstateOwnedScheduleofIncomeLossfromRealEstateOwnedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLossFromRealEstateOperations_019e6509-5f8f-789e-a662-7e60dd0b93a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLossFromRealEstateOperations"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_RealEstateOwnedOperatingCostsAndExpenses_019e6509-5f8f-753a-8495-88ec0908c41e" xlink:href="gpmt-20260630.xsd#gpmt_RealEstateOwnedOperatingCostsAndExpenses"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLossFromRealEstateOperations_019e6509-5f8f-789e-a662-7e60dd0b93a0" xlink:to="loc_gpmt_RealEstateOwnedOperatingCostsAndExpenses_019e6509-5f8f-753a-8495-88ec0908c41e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_RealEstateOwnedPropertyOperatingRevenue_019e6509-5f8f-73d4-837a-5335feebc46f" xlink:href="gpmt-20260630.xsd#gpmt_RealEstateOwnedPropertyOperatingRevenue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ProfitLossFromRealEstateOperations_019e6509-5f8f-789e-a662-7e60dd0b93a0" xlink:to="loc_gpmt_RealEstateOwnedPropertyOperatingRevenue_019e6509-5f8f-73d4-837a-5335feebc46f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome_019e6509-5f8f-730b-acc7-f4bc4b41aed5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLeaseIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_019e6509-5f8f-7039-bda0-69cda3dfed18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLeaseIncomeLeasePayments"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeaseLeaseIncome_019e6509-5f8f-730b-acc7-f4bc4b41aed5" xlink:to="loc_us-gaap_OperatingLeaseLeaseIncomeLeasePayments_019e6509-5f8f-7039-bda0-69cda3dfed18" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseVariableLeaseIncome_019e6509-5f8f-7c14-a40d-6b785a771afb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseVariableLeaseIncome"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingLeaseLeaseIncome_019e6509-5f8f-730b-acc7-f4bc4b41aed5" xlink:to="loc_us-gaap_OperatingLeaseVariableLeaseIncome_019e6509-5f8f-7c14-a40d-6b785a771afb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_gpmt_RealEstateOwnedPropertyOperatingRevenue_019e6509-5f8f-756c-ab75-7aa869aa4b6d" xlink:href="gpmt-20260630.xsd#gpmt_RealEstateOwnedPropertyOperatingRevenue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome_019e6509-5f8f-759b-a32c-a2b65d89f668" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLeaseIncome"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_RealEstateOwnedPropertyOperatingRevenue_019e6509-5f8f-756c-ab75-7aa869aa4b6d" xlink:to="loc_us-gaap_OperatingLeaseLeaseIncome_019e6509-5f8f-759b-a32c-a2b65d89f668" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingIncome_019e6509-5f8f-7863-bbd0-683bae5937a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherOperatingIncome"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_gpmt_RealEstateOwnedPropertyOperatingRevenue_019e6509-5f8f-756c-ab75-7aa869aa4b6d" xlink:to="loc_us-gaap_OtherOperatingIncome_019e6509-5f8f-7863-bbd0-683bae5937a7" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.gpmtreit.com/role/CashCashEquivalentsandRestrictedCashScheduleofCashCashEquivalentsandRestrictedCashDetails" xlink:type="simple" xlink:href="gpmt-20260630.xsd#CashCashEquivalentsandRestrictedCashScheduleofCashCashEquivalentsandRestrictedCashDetails"/>
  <link:calculationLink xlink:role="http://www.gpmtreit.com/role/CashCashEquivalentsandRestrictedCashScheduleofCashCashEquivalentsandRestrictedCashDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019e6509-5f8f-7401-abb6-b27868f56def" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e6509-5f8f-74b4-bbd4-49d4ea7c74c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019e6509-5f8f-7401-abb6-b27868f56def" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019e6509-5f8f-74b4-bbd4-49d4ea7c74c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_019e6509-5f8f-744d-8110-39c07538081b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCash"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_019e6509-5f8f-7401-abb6-b27868f56def" xlink:to="loc_us-gaap_RestrictedCash_019e6509-5f8f-744d-8110-39c07538081b" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
