Free mortgage payoff calculator
See how extra monthly payments accelerate your mortgage payoff — enter loan details and extra payment to find months saved and interest avoided, updated live, as you type.
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Check your mortgage for prepayment penalties before making extra payments. Some loans restrict extra principal payments.
Results are estimates. Consult a professional.
How the mortgage payoff calculator works
An extra monthly payment goes entirely to principal, not interest. That shrinks the balance faster than the lender's schedule assumes, which in turn lowers the interest charged next month. Compounded over years, even a modest extra payment shortens the loan and cuts thousands in total interest. The calculator finds the new payoff date and the interest saved.
Worked example: $300,000 at 7% with $500 extra per month
A homeowner has a $300,000 mortgage at 7% over 30 years. Standard monthly P&I is $1,996. They decide to add $500 extra each month, applied straight to principal.
Years saved and interest saved by extra payment amount
The table below shows the impact of different extra monthly payments on a $300,000 mortgage at 7% over 30 years. Even $100 extra per month makes a meaningful difference over the life of the loan.
| Extra/month | Payoff (years) | Years saved | Interest saved |
|---|---|---|---|
| $0 (baseline) | 30.0 | — | $418,600 |
| $100/mo | 26.8 | 3.2 years | $57,500 |
| $250/mo | 24.1 | 5.9 years | $82,400 |
| $500/mo | 22.5 | 7.5 years | $100,900 |
| $1,000/mo | 19.4 | 10.6 years | $126,800 |
Source: CFPB mortgage payoff guide; standard amortization math. $300,000 loan, 7%, 30-year fixed, extra payments from month 1.
Notice that doubling the extra from $500 to $1,000 only saves an additional 3 years, not double, because the loan is already ending sooner and there are fewer remaining months to compress.
Tips for paying off your mortgage faster
Extra payments are one of the highest-return, zero-risk moves available to a homeowner. The return equals your mortgage interest rate — guaranteed. Here is how to do it right.
- Label extra payments as 'principal only' — tell your lender explicitly, in writing or via your online portal, that the extra amount goes to principal. Without that instruction, some servicers hold it as an advance on next month's payment instead.
- Start early for maximum impact — an extra dollar applied in year 2 saves more interest than the same dollar in year 20, because it compounds across more remaining months.
- Use windfalls strategically — tax refunds, bonuses, and inheritances applied as lump-sum principal payments deliver the same compounding benefit as years of small extra payments.
- Biweekly payments add one extra payment per year — pay half your monthly amount every two weeks. You make 26 half-payments (= 13 full payments) per year, shortening a 30-year loan by roughly 4 years at no additional per-payment cost.
- Compare the return to your investments — extra mortgage payments earn a guaranteed return equal to your mortgage rate. If your rate is 7%, that beats most bonds and matches long-run stock averages on a risk-adjusted basis.
Accuracy and limitations
Results are based on consistent extra payments applied from the current month, using standard amortization math. The calculator assumes you make every regular and extra payment on schedule. Missed payments, lump-sum prepayments in future years, or servicer processing delays are not modeled. Some lenders charge prepayment penalties on loans issued before 2014 — check your loan documents before making large extra payments.
Not financial advice — consult a mortgage professional for your specific situation.
Mortgage payoff terms defined
About this mortgage payoff calculator
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