Property tool

Mortgage Overpayment Calculator

Compare a capital-and-interest repayment mortgage with and without a lump-sum or monthly overpayment to estimate the time and interest saved.

Remaining termEnter the whole years and additional months left until the mortgage is due to be fully repaid. Find these on the latest mortgage statement.yearsmonths

For capital-and-interest repayment mortgages only — not interest-only mortgages. The overpayment field is the extra amount you want to test. Your usual mortgage payment is your existing contractual repayment; leave it at £0 if you want us to estimate it.

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Good to know

How this tool works

Compare a capital-and-interest repayment mortgage with and without a lump-sum or monthly overpayment to estimate the time and interest saved. Work through the labelled controls, review the result in the preview and reset the tool whenever you want to begin again.

Repayment mortgages only.This calculator assumes each normal payment covers interest and reduces the mortgage balance. It is not suitable for an interest-only mortgage, where the normal monthly payment generally covers interest and the capital is repaid separately. MoneyHelper explains the repayment types.
Use the result as a guide.Check important financial, tax or contractual decisions with the relevant provider or a qualified professional.

Frequently asked questions

What is Mortgage Overpayment Calculator useful for?

Estimate how much time and interest an overpayment could save. Treat the result as an illustration: rates, fees, eligibility and lender calculations can change the real outcome.

Is my information stored?

This tool works in your browser. The information you enter is not sent to us or saved in an account by this tool.

How accurate is the result?

The calculation follows the assumptions shown on the page. Rounding, provider methods and real-world charges can produce small differences.

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