Mortgage Payoff Calculator
Start from what you owe today. Add an extra monthly amount, a one-time lump sum, or both, and see your new payoff date, the interest you save, and the extra it takes to be mortgage-free by a target year.
Free to use No sign-up needed Updates as you type
Default interest rate: 7.18% — Freddie Mac 30-year fixed average, week of Nov 5, 2026. Enter the rate from your own Loan Estimate.
How the mortgage payoff calculator works
Adding even a modest amount to your monthly payment can dramatically shorten a mortgage, because every extra dollar goes straight to principal and stops accruing interest for the rest of the loan. This calculator takes your remaining balance, rate, and current payment, then re-amortizes the schedule with your additional contribution applied each month.
The result shows how many months or years you shave off the term and how much total interest you avoid. The effect is largest early in the loan, when the balance and the interest portion of each payment are both at their peak.
You can also enter a one-time lump sum, such as a bonus or an inheritance, which comes off the balance immediately while your regular payment stays the same. Set a goal year and the calculator works backward to the extra monthly amount it takes to be mortgage-free by then.
Worked example: with current loan balance of $240,000, interest rate of 7.18% and years remaining of 25, the mortgage payoff calculator shows interest you would save of $74,710.
- Current payment (P&I)
- $1,723.93
- New monthly payment
- $1,923.93
- New payoff date
- Jan 2046
- Interest without prepaying
- $277,178
| Extra monthly payment | Interest you would save |
|---|---|
| $150 | $60,518 |
| $300 | $97,772 |
| $500 | $130,354 |
| $750 | $156,971 |
The formula
The remaining balance is re-amortized with each payment split into interest, equal to the balance times the monthly rate, and principal, which absorbs everything left over including your extra amount. Iterating month by month until the balance reaches zero yields the new payoff date and cumulative interest.
How every calculator here computes, what it assumes and how the defaults stay current: our methodology.
- The extra payment is applied to principal every month without interruption for the full remaining term.
- A lump sum is credited to principal today, and the scheduled payment is not recast lower afterward.
- Your lender credits additional payments to principal immediately and charges no prepayment penalty.
- The interest rate is fixed; a variable rate would change the savings as it adjusts over time.
- Escrowed taxes and insurance are excluded, since only principal and interest are affected by prepayment.
- Results ignore inflation and any return you might earn by investing the extra money instead.
Ways to pay off a $300,000 mortgage early, compared
A new $300,000 30-year loan at today's 7.18% average costs $2,032.30 a month and $431,630 in interest if you only make the scheduled payment. Here is what each common prepayment strategy does to it.
| Strategy | Extra cost | Paid off in | Interest saved |
|---|---|---|---|
| Scheduled payments only | — | 30 yr | $0 |
| Add $100 a month | $1,200 / yr | 25 yr 10 mo | $72,521 |
| Add $250 a month | $3,000 / yr | 21 yr 7 mo | $140,900 |
| Add $500 a month | $6,000 / yr | 17 yr 3 mo | $207,856 |
| One extra payment a year (biweekly) | $2,032 / yr | 23 yr 8 mo | $108,283 |
| $10,000 lump sum now | $10,000 once | 26 yr 11 mo | $66,600 |
| Refinance to a 15-year | $592.58 / mo more | 15 yr | $259,151 |
The 15-year row uses today's 6.57% average 15-year rate and ignores refinance closing costs, which typically run 2%–5% of the loan. Every extra dollar effectively earns your mortgage rate, risk-free — weigh that against higher-interest debt, an emergency fund and retirement matches before prepaying.
How much extra to pay off your mortgage in 10, 15 or 20 years
The extra monthly principal it takes, on top of the regular payment, to retire a loan with 25 years left at 7.18%.
| Balance today | Regular payment | Done in 20 yrs | Done in 15 yrs | Done in 10 yrs |
|---|---|---|---|---|
| $200,000 | $1,436.61 | +$135.67 | +$381.24 | +$904.16 |
| $300,000 | $2,154.91 | +$203.51 | +$571.86 | +$1,356.24 |
| $400,000 | $2,873.21 | +$271.35 | +$762.47 | +$1,808.32 |
Results are estimates for educational purposes and are not financial advice. Confirm exact figures with your lender or a licensed advisor.
Questions about the mortgage payoff calculator
Is it better to pay extra each month or make one lump sum a year?
Monthly extras win slightly, because the money reduces your balance sooner and starts saving interest earlier in the year. A single annual lump sum still helps meaningfully and suits people paid through bonuses or tax refunds.
The gap between the two methods is small, so choose whichever cadence you will actually sustain.
Should I pay down my mortgage or invest the extra money instead?
Compare your mortgage rate to your expected after-tax investment return. Prepaying delivers a guaranteed return equal to your rate, which is attractive when rates are high or markets feel uncertain. Investing may win over long horizons but carries risk.
Many borrowers split the difference, paying some extra principal while still funding retirement accounts.
Will extra payments lower my required monthly bill?
Usually not. Standard prepayment shortens the term but leaves your scheduled payment unchanged, so you finish the loan sooner rather than paying less each month.
To reduce the required amount you would need a formal recast, where the lender re-amortizes the lowered balance over the original term, often for a small fee.
Is my information saved or shared?
No. Every calculation runs entirely in your browser. We never store, transmit or sell the numbers you enter.
How can I pay off my mortgage faster?
Add extra to principal each month, switch to biweekly payments, or make a lump-sum payment — each cuts the term and total interest, since interest is charged on the remaining balance. Test any amount above to see the new payoff date.
Sources
- CFPB — What is a prepayment penalty?
- CFPB — Loan Estimate explainer
- Freddie Mac — Primary Mortgage Market Survey (weekly average rates)
- CFPB — Fixed-rate vs adjustable-rate mortgages
How the figures on this site are calculated and tested: methodology · editorial policy.
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