How much could I save by overpaying my mortgage?

Overpaying reduces your balance faster, so you pay less interest overall and can clear the mortgage sooner. The saving depends on your balance, interest rate, remaining term and how much extra you pay. This calculator runs the mortgage month by month with and without your overpayment to show the illustrative interest saved and time knocked off the term. It is a guide only — results assume your rate stays the same for the rest of the term.

Are there penalties for overpaying a mortgage?

Most lenders allow penalty-free overpayments up to a limit — often 10% of the balance per year — while you are inside a fixed-rate deal. Exceeding that limit can trigger an early repayment charge (ERC). Always confirm your lender's overpayment allowance and any ERCs before overpaying. Overpaying may not be the best choice if you have higher-interest debt or no emergency savings.

Mortgage Overpayment Calculator

See how much interest you could save — and how many years you could knock off your mortgage — by paying a little extra each month or a one-off lump sum. Figures are illustrative; check your lender's overpayment limits and any early repayment charges first.

For illustration purposes only

The figures this calculator produces are illustrative and based only on the information you enter. They are a guide — not a quote, a mortgage offer, or financial advice. What you can actually borrow, and the rate you pay, depend on the lender’s assessment of your full circumstances.

Speak to a qualified professionalFor a recommendation tailored to you, speak to an FCA-regulated mortgage adviser — we search the whole of market. Checking your options is free and does not affect your credit score.

No obligationThis is an estimate only. The binding figures — your real monthly payment, total cost and any reversion rate — come with your mortgage offer and its illustration (ESIS).

Niche Advice Limited accepts no responsibility for any decisions made on the basis of this calculator. Niche Advice Limited is authorised and regulated by the Financial Conduct Authority (FCA Reference: 750263). Niche Advice Limited is a credit broker, not a lender. Your home may be repossessed if you do not keep up repayments on a mortgage secured against it.

Lender criteria and interest rates change frequently. Always confirm any figure with a qualified, FCA-regulated mortgage adviser before acting on it.

Get advice from a whole-of-market specialist

This is a guide only. For figures tailored to you — with no upfront fees — request a callback from an FCA-regulated adviser.

Speak to an adviser