Mortgage Overpayment Calculator

This tool shows the impact of regular monthly overpayments or lump sum payments on your mortgage term and total interest paid. It compares your current trajectory against an overpayment scenario so you can see whether redirecting cash into the mortgage makes sense for your situation.

How overpayments shorten the term

Extra payments reduce the outstanding balance faster, cutting both term length and total interest significantly over time.

Monthly overpayments vs lump sums

Both approaches reduce cost but behave differently depending on when and how you make them.

When to prioritise savings instead

Overpayments are not always the best use of spare cash, particularly if rates are low or an emergency buffer is thin.