Mortgage offset calculator 2026
A mortgage offset structure links a deposit account to a home loan so that the account balance is considered when calculating interest. This calculator estimates how applying an offset balance may affect interest costs and repayment timing.
Estimates only. Loan terms and approval depend on lender underwriting.
Mortgage Offset Calculator
Mortgage Result
Enter loan details to calculate.
How it works
The calculator applies standard amortization math and then reduces the effective principal used for interest calculations by the offset balance you enter. Interest is calculated on the net amount (loan balance minus offset balance), while scheduled payments remain based on the loan terms provided. Over time, maintaining funds in the linked account can reduce total interest paid and may shorten the repayment period depending on how payments are structured.
Examples
Example scenario: If a borrower has a $300,000 mortgage and maintains $20,000 in a linked offset account, interest may be calculated on $280,000 rather than the full balance, depending on lender design. Monthly payments are applied according to the loan contract, and any reduction in interest can accelerate principal repayment. The calculator illustrates estimated interest differences based on the inputs you provide.
Limitations and important notes
Results are estimates of principal and interest using a simplified model. Actual offset structures depend entirely on the lender’s product design, account rules, and loan agreement. This tool does not determine eligibility, does not provide a rate quote, and does not assess compliance with any federal mortgage program. Federal mortgage regulations such as Regulation Z establish disclosure and ability-to-repay standards but do not define a specific "mortgage offset account" product category. For general federal mortgage disclosure standards, see the Consumer Financial Protection Bureau’s overview of <a href="https://www.consumerfinance.gov/rules-policy/regulations/1026/" target="_blank" rel="noopener noreferrer">Regulation Z (Truth in Lending Act)</a>.
FAQs
What is a mortgage offset account?
It is a loan structure where funds held in a linked deposit account are considered when calculating interest on a mortgage. The calculation method and rules depend on the lender’s product terms.
Does a mortgage offset reduce the loan balance?
No. The deposit balance does not typically reduce the principal directly. Instead, it may reduce the amount on which interest is calculated, depending on the loan agreement.
Are mortgage offset accounts regulated under federal mortgage law?
Federal mortgage laws establish disclosure, servicing, and ability-to-repay standards, but they do not define a distinct mortgage offset account product type. Product availability and structure depend on lender offerings within applicable regulations.
Does qualifying for an offset mortgage depend on the lender?
Yes. Approval, underwriting standards, and availability of linked-account features depend on the lender’s credit policies and product design within applicable federal and program requirements.
Calculations are simplified and for guidance only. Always double-check results and current rules with official sources or a qualified professional before making financial decisions.