Mortgage Repayment Calculator
Work out your monthly mortgage payment, total interest paid, and how much you save by overpaying.
Your details
Remaining balance over time
How this is calculated
A repayment mortgage splits each monthly payment between interest on the outstanding balance and a chunk of the principal. Early on, most of the payment is interest; over time the balance falls and more of each payment reduces the principal.
An interest-only mortgage keeps the balance constant — you only pay interest each month, and repay the full principal at the end. Monthly payments are lower, but total interest paid is much higher.
Overpayments go straight against the principal, which reduces the interest charged on every subsequent month. Even a small monthly overpayment can shave years and thousands in interest off the total.
Who this calculator is for
This is aimed at anyone weighing up borrowing, saving or investing decisions before committing to them. It is most useful when you are comparing offers side by side, testing how sensitive a plan is to a change in rate or term, or sanity-checking a figure a lender or adviser has quoted you.
Assumptions and accuracy
Results assume the interest rate you enter stays fixed for the whole term and that payments are made on schedule. Real products may carry arrangement fees, early-repayment charges, variable rates, or different compounding intervals, all of which change the total. Use this to compare options, then confirm the exact figures with the provider.
Frequently asked questions
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