See how adding extra principal each month could shorten your fixed-rate mortgage and reduce the total interest you pay. You’ll need your current balance, interest rate, and remaining term from your mortgage statement.
Estimated impact
Enter your balance, rate, remaining term and extra payment.
Estimated interest saved
Paid off sooner by
New estimated payoff date
Payoff date without extra
Regular principal & interest payment
How this calculator works
Monthly rate r = annual rate ÷ 12 ÷ 100; n = months remainingRegular payment P = balance × r ÷ (1 − (1 + r)^−n)Each month: interest = balance × r; principal = P + extra − interestInterest saved = total interest without extra − total interest with extra
Assumptions and limits
- Fixed-rate, fully amortizing loan with monthly payments. Not suitable for ARMs, interest-only, or balloon loans.
- The regular payment is calculated from your balance, rate and remaining term; it may differ slightly from your statement. Taxes, insurance and PMI in escrow are excluded.
- Assumes the extra amount is applied to principal every month with no prepayment penalty. Confirm how your servicer applies extra payments.
- Does not compare against other uses of the money (emergency savings, higher-rate debt, investing) or any tax effects.
This is an illustrative estimate, not financial advice or a guarantee of savings.