Mortgage Payoff Calculator

Finance

Last updated: July 11, 2026

See how extra monthly payments can reduce your mortgage term and save you thousands in interest. Compare your current payoff schedule with accelerated payoff scenarios.

Loan Amount ($)

Interest Rate (%)

Loan Term (years)

Months Already Paid

Extra Monthly Payment ($)

How to Use This Calculator

Enter your Loan Amount, Interest Rate, and Loan Term.
Input how many Months Already Paid on your current mortgage.
Set the Extra Monthly Payment you plan to add above your regular payment.
Click Calculate to see months saved, interest saved, and a side-by-side comparison.

Formula

M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]

Where M = monthly payment, P = loan principal, r = monthly interest rate, n = number of remaining payments. With extra payments, the remaining balance decreases faster, reducing both the term and total interest.

Examples

$300K Loan, $200 Extra: $300,000 at 6.5% for 30 years with $200/mo extra payment. Original payoff: 360 months. New payoff: 282 months. Saves 78 months and $67,498 in interest.

$200K Loan, $100 Extra: $200,000 at 7% for 30 years with $100/mo extra payment. Saves 54 months and $42,831 in interest. Small extra payments add up significantly.

$400K Loan, $500 Extra: $400,000 at 6% for 30 years with $500/mo extra payment. Saves 108 months (9 years!) and $158,178 in interest.

Frequently Asked Questions

How do extra mortgage payments save money?

Extra payments go directly toward reducing your principal balance. Since interest is calculated on the remaining balance, a lower principal means less interest accrues each month, shortening the loan term and saving money.

Is biweekly payment better than monthly?

Yes. Paying biweekly results in 26 half-payments per year, which equals 13 full monthly payments instead of 12. This extra payment per year can reduce a 30-year mortgage by about 4–5 years and save significant interest.

What is mortgage recasting?

Recasting is when you make a lump-sum payment toward your mortgage and the lender re-amortizes the loan with the lower balance. This reduces your monthly payment without changing the loan term. Not all loans allow recasting.

Should I prepay my mortgage or invest?

Compare your mortgage interest rate to expected investment returns. If your mortgage rate is 6% and investments historically return 8–10%, investing may yield more. However, guaranteed interest savings from paying off debt has its own value and peace of mind.