Mortgage Overpayment and Payoff Calculator
Shows how much time and interest overpaying takes off a mortgage.
Interest saved
—
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
New payoff time —
Time saved —
Normal monthly payment —
Interest without extra —
Interest with extra —
Reading this —
The formula
each month: balance = balance × (1 + i) − (payment + extra)
Extra money goes straight to the principal, so every later month charges interest on less.
What to watch out for
Many fixed-rate deals limit overpayments, often to around 10% a year. If your savings earn more after tax than the mortgage rate, saving may beat overpaying.
Frequently Asked Questions
How much does overpaying a mortgage save?
200 a month on 200,000 at 5% over 25 years saves 41,842.60 in interest.