Add the requested inputs
Use the labelled fields in the workspace above. If example values are provided, try them first or replace them with your own.
Money & business · Free online tool
Mortgage overpayment calculator
Estimate how a regular monthly overpayment shortens a mortgage and reduces total interest. Compare the original term and total interest with a fixed-rate repayment plan that includes a regular overpayment.
3 guest runs per rolling 24 hours10 with a free accountPrivate inputsMobile-friendly
Mortgage overpayment calculator workspace
Runs locally in your browser
Lender overpayment limits, fees and rate changes can change the real result.
Result
Original monthly payment—
New payoff time—
Interest saved—
Months saved—
Planning note
Use it with confidence
How to use the mortgage overpayment calculator.
Calculate and review
Use the main action when needed. The original payment uses the standard fixed-rate repayment formula. The overpayment simulation applies the regular payment plus overpayment until the balance reaches zero, tracking months saved and interest avoided.
Try a worked example
A £150,000 mortgage at 5% over 25 years with a £100 monthly overpayment pays off several years earlier and saves a meaningful amount of interest.
Check the assumptions
Lender overpayment limits, fees, rate changes, payment rounding and future borrowing decisions can change the real result. This is a planning estimate, not advice.
Helpful answers
Mortgage overpayment calculator FAQs.
Is the mortgage overpayment calculator free?
Yes. Guests receive 3 runs per rolling 24 hours, verified free accounts receive 10, and Premium subscribers receive unlimited normal use.
Does UtilHub upload or save my inputs?
No. This tool runs in your browser and UtilHub does not receive or store the values you enter. Your browser or device may still retain normal local history or form data.
How does this mortgage overpayment calculator work?
The original payment uses the standard fixed-rate repayment formula. The overpayment simulation applies the regular payment plus overpayment until the balance reaches zero, tracking months saved and interest avoided.
What should I check before using the result?
Lender overpayment limits, fees, rate changes, payment rounding and future borrowing decisions can change the real result. This is a planning estimate, not advice.