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Mortgage overpayment calculator

Use our calculators to find out how a regular or lump sum overpayment could reduce the term and interest paid on your mortgage.

Which type of overpayment do you want to make?

If you would like to make the same overpayment each month on an ongoing basis please use our regular overpayment calculator.

If you would like to make a one off, lump sum or adhoc payment please use our lump sum overpayment calculator.

Regular overpayment



If you pay more than your annual overpayment allowance, you could incur an early repayment charge. Details of this can be found on your offer document.

Think carefully before securing other debts against your home. Your home may be repossessed if you do not keep up repayments on your mortgage.

Calculator assumptions

The figures provided by this calculator are for illustrative purposes only, and assume;

  • your interest rate will stay the same for the term of your mortgage
  • the months are all the same length
  • repayments are rounded up or down to the nearest pound
  • the period of time is rounded down to the closest month
  • interest saved is rounded up or down to the nearest pound
  • the calculator doesn’t account for any early repayments charges
  • if making a regular overpayment, you’ll be paying that every month for the remaining term

If you have more than one mortgage loan part, you must calculate the overpayment on each loan separately.

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