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Mortgage Overpayment Calculator

Small, steady overpayments quietly demolish mortgages. See how much interest — and how many years — yours could save.

£
%
years
£
£

Interest saved

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Mortgage-free

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Monthly payment

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New payoff time

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▬ sticking to the schedule  ▬ with your overpayments

How it works

The calculator works out your standard monthly repayment from the balance, rate, and remaining term, then replays the mortgage month by month with your overpayment (and any lump sum) applied. Everything extra goes straight at the balance, which is why the savings compound so satisfyingly.

Worth knowing before you overpay: it assumes your rate stays the same for the rest of the term (real life will vary as fixes end). Most UK lenders let you overpay about 10% of the balance each year without penalty — check yours for early repayment charges. And an overpayment usually beats nothing, but money is personal: a topped-up emergency fund or expensive debt cleared first often matters more.

This calculator is a general educational tool. It uses simplified assumptions, isn't personalised financial advice, and shouldn't be the only basis for a money decision — see our Disclaimer. For decisions that matter, consider speaking to a suitably qualified, regulated adviser.

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