Mortgage payoff estimator
Mortgage extra payment calculator
Estimate how a fixed monthly extra principal payment could change modeled mortgage payoff time and interest under your entered balance, rate, and term.
Compare the scheduled principal-and-interest payment with the same loan plus a fixed extra amount applied to principal each month. This is a simplified estimate, not a lender quote.
Enter the loan assumptions and calculate.
Assumes a fixed rate, monthly interest at APR ÷ 12, on-time monthly payments, and that the extra amount is applied directly to principal. It excludes fees, taxes, insurance, escrow, and payment-date effects.
How the extra-payment estimate works
The baseline uses a standard fixed-rate principal-and-interest payment over the remaining term. The comparison keeps that scheduled payment and adds your entered amount to principal each month. Both scenarios use the same starting balance and rate; the model does not change your required payment or predict how a servicer will apply a payment.
Check your note and servicer instructions before paying extra. The CFPB says prepayment penalties do not normally apply to small chunks of extra principal, but recommends checking with the lender. A penalty may apply in some circumstances, including certain large lump-sum payments. Source last reviewed September 11, 2024; this site reviewed it November 3, 2026.
CFPB: What is a prepayment penalty?
For an estimated scheduled monthly payment without extra principal, use the mortgage payment calculator. To inspect the modeled month-by-month principal and interest, open the mortgage amortization schedule. For a refinance comparison, see the refinance break-even calculator.
How it works
Enter the starting balance, fixed annual rate, remaining term, and extra monthly amount to compare a scheduled payment with an extra-principal scenario.
Good to know
Does an extra payment always reduce interest by this estimate?
No. The model assumes the extra amount is applied directly to principal each month and uses monthly interest at APR divided by 12. Your loan terms, payment timing, and servicer application rules control the actual result.
Could a prepayment penalty apply?
The CFPB says penalties do not normally apply to small extra-principal payments, but circumstances and loan terms vary. Check your documents and ask your servicer, especially before a large lump-sum payment.
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