How it works
One model, every assumption visible.
See how an additional monthly mortgage payment can change payoff time and interest. The calculation runs locally in your browser. Inputs are not placed in the URL or stored by this page.
Real outcomes can differ because rules, rates, taxes, fees, timing and personal circumstances change. Verify consequential decisions against current official guidance or a qualified professional.
Frequently asked
Extra Mortgage Payment Calculator questions
Does this use live financial data?
No. It uses only the assumptions shown above.
Are the results guaranteed?
No. They are mathematical illustrations, not forecasts, quotes, eligibility decisions or financial advice.