Mortgage Payoff Calculator — How Long Until Your Mortgage Is Paid Off?
Enter your current remaining balance, annual interest rate and monthly payment amount to instantly see how many months remain on your mortgage and the total interest you will still pay.
%
19 years and 3 months remaining
- 1
Monthly interest rate
r = 6.5% ÷ 12 ÷ 100 = 0.005417 - 2
Rate × balance ÷ payment
0.005417 × 250,000 ÷ 1,900 = 0.712719Must be less than 1 for the loan to eventually reach zero. - 3
Months to payoff
−ln(1 − 0.712719) ÷ ln(1 + 0.005417) = 231
How does this calculator work?
Payoff time n = −ln(1 − r·B / PMT) ÷ ln(1 + r), where r is the monthly rate, B the remaining balance and PMT the monthly payment. Total remaining interest is PMT × n − B. Enter your current figures to see exactly when you will be mortgage-free.
Formula
How this is calculated
The payoff time comes from rearranging the standard amortisation formula to solve for n (the number of payments). Given a remaining balance B, monthly periodic rate r (annual rate ÷ 12 ÷ 100) and monthly payment PMT, the formula is n = −ln(1 − r·B / PMT) ÷ ln(1 + r). This is exact — not an approximation — and gives the number of full monthly payments needed to reduce the balance to zero.
The total remaining interest is simply (PMT × n) − B: you will pay PMT every month for n months, but only B of that is principal repayment; the rest is interest. The balance curve shows how the outstanding principal falls over time — steeply at first (when interest takes a large share of each payment) and then more steeply as the loan matures and a larger share goes to principal.
If the monthly payment is less than or equal to the monthly interest charge (balance × monthly rate), the loan will never be paid off — the calculator flags this as an error. Enter the principal-and-interest portion of your payment only; exclude escrow amounts for taxes and insurance.
Frequently asked questions
If your monthly payment is at or below the monthly interest (balance × monthly rate ÷ 100 ÷ 12), the principal never decreases — the loan is negatively amortising. You must increase the payment above that threshold for the loan to eventually be paid off.
Check your most recent mortgage statement or log into your lender's online portal. The "principal balance" or "outstanding balance" line is the figure to enter here — not the original loan amount.
Yes — enter the current balance (not the original amount), your current rate and your current payment. The calculator works for any point in the loan life.
Also known as
TG we-Calculate Editorial Team. (2026). Mortgage Payoff Calculator — How Long Until Your Mortgage Is Paid Off? [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mortgage-payoff-calculator
TG we-Calculate Editorial Team. "Mortgage Payoff Calculator — How Long Until Your Mortgage Is Paid Off?." TG we-Calculate. 2026. https://we-calculate.com/calculator/mortgage-payoff-calculator.
TG we-Calculate Editorial Team, "Mortgage Payoff Calculator — How Long Until Your Mortgage Is Paid Off?," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mortgage-payoff-calculator
@misc{wecalculate_mortgage_payoff_calculator, title = {Mortgage Payoff Calculator — How Long Until Your Mortgage Is Paid Off?}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mortgage-payoff-calculator}}, year = {2026}, note = {TG we-Calculate} }
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