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Mortgage Overpayment Calculator

See how regular overpayments could reduce your mortgage balance, save interest and bring your mortgage-free date forward. Choose how many years you want to make the extra payments.

Enter your mortgage details

Use your latest mortgage statement. Your actual monthly payment is used for the projections.

Enter your figures and select Calculate to see the difference.

Calculated locally in your browser. We do not store or transmit your mortgage figures.

What these results mean

The comparison shows the balance after your chosen overpayment period, the total estimated interest over the life of the mortgage and how many months earlier you could finish. Overpayments stop after your chosen duration; your normal monthly payment continues.

These are illustrations for a repayment mortgage, using a constant annual interest rate, monthly interest and fixed monthly payments. Actual lenders may calculate interest daily, recalculate payments after overpayments, or restrict overpayments. Check early repayment charges, limits, your rate's end date and the lender's treatment of overpayments. The calculation does not account for fees or future rate changes.

Keep enough money for essentials and emergencies before committing extra cash. For a separate comparison against savings, use Mortgage Overpayment vs Savings.

Is it worth overpaying your mortgage?

Overpaying can cut interest and shorten a repayment mortgage. Check your lender’s overpayment allowance and any charges, keep enough cash for emergencies and compare what the money could earn in accessible savings.

In the episode’s illustration, paying £100 extra every month on a £200,000 repayment mortgage at a constant 5% with 25 years left saves about £24,500 in interest and brings the final payment forward by 42 months. It assumes the normal payment stays the same, the extra payments continue until payoff and there are no fees or rate changes. Use the calculator above to test your own figures.

Watch on YouTube: Is it worth overpaying your mortgage?

Should I overpay my mortgage or invest?

Overpaying reduces your mortgage balance and the interest charged on it. Investing can produce a higher return over a long period, but your investments can fall in value. Compare over the same timeframe and allow for charges, taxes and the risk that you need the money sooner than planned.

  • Overpay: Use this calculator to estimate the interest avoided. Check your lender’s overpayment allowance, early repayment charges and whether you can access money you’ve already overpaid.
  • Save: If you may need the money sooner, compare accessible savings after any tax with the Mortgage Overpayment vs Savings Calculator.
  • Invest: Consider how long you can leave the money invested and whether you could afford a loss. See our UK beginner’s investing guide.

Check your emergency cash and any more expensive debt first. See MoneyHelper’s early mortgage repayment guide.

How much interest could a mortgage overpayment save?

Use this UK mortgage overpayment calculator to compare your existing repayment schedule with a regular extra monthly payment. Enter your current mortgage balance, annual interest rate, remaining term and planned overpayment. The results illustrate the possible reduction in interest and the time to repay, assuming the rate and normal payment stay constant.

Does overpaying reduce my mortgage term or monthly payment?

That depends on your lender. This calculator illustrates a shorter repayment term while keeping the normal monthly payment unchanged. Some lenders instead recalculate the required monthly payment, so check how yours applies extra payments before acting.

For a separate choice between keeping money accessible and paying down your mortgage, use the Mortgage Overpayment vs Savings Calculator. If you do not have an emergency buffer, read how to build an emergency fund first. Check early repayment charges and annual overpayment allowances with your lender.