Mortgage overpayment calculator

Our mortgage overpayment calculator can give you an idea of how much money you could save by overpaying on your mortgage and reducing the amount of interest you get charged. This calculator can be used by anyone with a mortgage.

The calculator is for illustrative purposes only and based on certain key assumptions, listed below. It provides an indication of the interest you could save. The calculator doesn’t take into consideration any early repayment charges that may apply and is based on a repayment mortgage.

Before making overpayments talk to your mortgage lender to understand if any early repayment charges apply. If you want to make overpayments to have the effect of reducing your mortgage term, rather than just reducing your monthly mortgage payment, you need to talk to your lender.

Once you've used the calculator find out the next steps available to you.

Your home may be repossessed if you do not keep up repayments on your mortgage.

We use the following assumptions in the calculations:

  • Based on a repayment mortgage
  • Any regular monthly overpayments remain the same over the term of the mortgage
  • All years are of equal length
  • Interest is calculated daily and added monthly
  • The mortgage balance shown on the graph and table are the same, and are the amount left on the mortgage at the end of that particular year
  • Multiple sub accounts must be calculated individually
  • Estimate of total interest saved is rounded to the nearest pound
  • There is no change in interest rate which would recalculate your monthly payment
  • There will not be any changes to your mortgage which would result in a recalculation of your monthly payment e.g. changes to your mortgage product, term, type or change of owners