Mortgage Payoff Calculator
See exactly what paying a little extra each month does to your mortgage: a new, earlier payoff date and thousands less in total interest. Enter your loan and an extra monthly amount to compare against the original schedule.
Because early payments go entirely toward principal, they remove the interest that principal would have accrued for the rest of the loan — which is why even a small extra amount can shave years off a 30-year mortgage.
Interest saved
$105,429
Paid off 6y 7m sooner
- New monthly payment
- $2,222.62
- Payoff time (with extra)
- 23y 5m
- Payoff time (original)
- 30y
- Total interest (with extra)
- $302,714
- Total interest (original)
- $408,142
Calculation Formulas
First the calculator finds your normal principal-and-interest payment from the loan amount P, monthly rate r (APR ÷ 12), and number of payments n (years × 12).
The calculator then simulates the loan month by month paying M plus your extra amount. Because the extra goes straight to principal, the balance falls faster and the loan clears before month n.
The difference between the interest paid on the original schedule and the interest paid once you add the extra amount — the money the extra payments keep in your pocket.
Example:
A $320,000 loan at 6.5% for 30 years costs about $408,000 in interest; adding $200/month clears it roughly 5 years early and saves tens of thousands in interest.
Key Figures
| Figure | Value | Description |
|---|---|---|
| Interest is front-loaded | Early years | Most of each early payment is interest, so extra principal paid early saves the most. |
| Prepayment penalties | Rare, must be disclosed | Almost all U.S. mortgages allow penalty-free extra principal payments. |
Note: Results are estimates for planning purposes. Rates, fees, taxes, and insurance vary by lender and location — confirm exact figures with a licensed professional before making financial decisions.
Standards & Sources
Last verified: July 2026
- CFPB guidance on extra mortgage payments
The Consumer Financial Protection Bureau advises confirming that extra payments are applied to principal, and notes prepayment penalties are uncommon and must be disclosed in loan documents.
- Standard amortization (same engine as the mortgage calculator)
Payoff results use the identical amortization math as our mortgage calculator, so the baseline schedule and the with-extra schedule are directly comparable.
How to Use This Calculator
- Enter your loan amount, interest rate, and the loan term in years.
- Enter the extra amount you would add to each monthly payment.
- See your new payoff time next to the original, the months (or years) you save, and the total interest you avoid.
- Adjust the extra amount to find a payment you can sustain — the interest saved updates instantly.
Frequently Asked Questions
How do extra mortgage payments save money?
An extra payment goes entirely toward principal, which permanently removes all the future interest that principal would have accrued over the remaining term. On a long loan, interest is front-loaded, so extra payments made early save the most.
Is it better to pay extra monthly or make one lump-sum payment?
Both help; timing is what matters. A dollar of principal paid earlier saves more interest than the same dollar paid later, so consistent extra monthly payments started early tend to beat a single lump sum made years in. This calculator models a recurring extra monthly amount.
Should I pay off my mortgage early or invest instead?
Paying extra earns a guaranteed return equal to your mortgage rate; investing may earn more but carries risk. If your mortgage rate is higher than a safe return you could earn elsewhere — or you value being debt-free — extra payments are attractive. Compare the interest saved here against your expected investment return.
Will my lender let me make extra principal payments?
Almost all U.S. mortgages allow extra principal payments with no penalty; prepayment penalties are rare and must be disclosed. Make sure the extra amount is applied to principal (not held as a prepaid regular payment) so it reduces the balance immediately.
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