Free calculator

See what overpaying your mortgage could actually save you

Overpaying reduces what you owe, and because interest is charged on your outstanding balance, a smaller balance means less interest over the life of the loan. This calculator uses your own balance, rate and remaining term to show what a regular or one-off overpayment could do to your payoff date and total interest, so you can decide whether it's worth doing before you call your lender.

How-To Guide

Understanding the Mortgage Overpayment Calculator

This guide explains what the Mortgage Overpayment Calculator works out and how to read the result once you have it. It's for anyone with a mortgage who is wondering whether paying extra off the balance is worth doing, before checking the details with their lender. Paying extra off a loan saves you interest, because interest is charged on what you still owe, and this calculator shows roughly how much that could mean for you.

Level: Beginner
Best for: Homeowners weighing up whether to overpay their mortgage
  1. Gather your mortgage details

    Find your outstanding balance, interest rate and remaining term on your most recent mortgage statement.

  2. Enter your figures

    Add a regular or one-off overpayment amount to see how it changes your outstanding balance over time.

  3. Read what the numbers mean

    See how much interest and time an overpayment could save, and understand what the result depends on before you act on it.

See what overpaying could do to your mortgage

Paying extra off your balance each month reduces the interest you're charged, because interest is calculated on what you still owe. Enter your own balance, rate and term to see roughly how much time and interest that could save.

Your Mortgage Details

Enter the amount you still owe on your mortgage

Use your current mortgage interest rate

How many years are left on your mortgage

The extra amount you plan to pay each month

Your Savings Breakdown

Total Interest You Could Save

New Mortgage Term

Time Saved

Current Monthly Payment

New Monthly Payment

Original Remaining Term
Total Interest (Without Overpaying)
Total Interest (With Overpayment)

This calculator gives an illustrative estimate based on the figures you enter, not a quote from any lender. Check your mortgage offer document for your actual overpayment terms, or speak to a broker before making a decision.

Free Tools

See what overpaying could do to your mortgage

This calculator shows what regular overpayments could do to your outstanding balance and remaining term, using the figures you give it. It's built for anyone with a mortgage who wants to see the effect of paying a bit extra each month before deciding whether it's worth doing. Check the guide alongside it if you want help reading what the result actually means for your situation.

No account required · Works on any device · Always free