Mortgage calculator with extra payments
Enter your loan amount, interest rate, and term, then add an extra monthly payment, a one-time extra payment, or both. The calculator shows how much interest you save, how many years earlier you pay off the loan, and a full amortization schedule that reflects your extra payments.
How to use this calculator
Enter your loan amount, annual interest rate, and term in years. Add an extra amount you'll pay every month toward the principal, if any. Add a one-time extra payment and the month you'll make it, if any. Click Calculate to see your interest saved, time saved, new payoff time, and updated schedule.
How extra payments save you money
Every extra dollar you pay goes straight to the principal — the outstanding balance. Because interest is charged on that balance, reducing it early means less interest accrues in every month that follows. The result is a shorter loan and a lower total interest cost.
Extra payments made early in the loan save the most, because that's when your balance — and therefore your interest — is highest. Even a small extra amount each month can cut years off a 30-year mortgage.
Monthly vs. one-time extra payments
A recurring extra monthly payment compounds its effect over time and is the most powerful way to shorten a loan. A one-time lump sum — from a bonus, tax refund, or windfall — gives an immediate balance reduction. You can combine both in this calculator to compare scenarios.
Before you commit, confirm your loan has no prepayment penalty and that extra payments are applied to principal, not prepaid interest or the next month's payment.