Mortgage tool

Mortgage overpayment calculator

Estimate how a regular monthly overpayment and a one-off lump sum could reduce mortgage interest and shorten the remaining term.

Inputs

Use your current balance, remaining term, interest rate, and the overpayments you are considering. The calculator assumes the rate stays fixed.

Method

It first calculates the standard repayment, then applies the one-off overpayment at the start and adds the monthly overpayment to each payment.

Limits

Check your lender rules before overpaying. This estimate does not include fees, early repayment charges, daily interest, rate changes, payment holidays, or remortgaging.