Money calculators · Updated
Mortgage Payoff Calculator
Add an extra monthly amount or a one-time lump sum to your mortgage and estimate the remaining payoff time and interest difference in a fixed-rate monthly model.
| Lump sum applied now | $0.00 |
| Modeled principal and interest payment | $2,097.78 |
| Time left on the current schedule | 27 years |
| Time left with extra payments | 21 years 8 months |
| Interest remaining, current schedule | $359,677.13 |
| Interest remaining, with extra payments | $277,134.24 |
| Total paid with extra payments, including lump sum | $597,134.24 |
The regular payment is derived from the balance, rate and remaining term, then rounded upward to a cent. The lump sum is applied immediately, capped at the remaining balance. Escrow, fees, penalties and changes in rate are excluded.
Balance after the upfront lump sum and scheduled payments
| Year | Principal paid | Interest paid | Balance |
|---|---|---|---|
| 1 | $6,978.84 | $20,594.52 | $313,021.16 |
| 2 | $7,446.22 | $20,127.14 | $305,574.94 |
| 3 | $7,944.91 | $19,628.45 | $297,630.03 |
| 4 | $8,477.00 | $19,096.36 | $289,153.03 |
| 5 | $9,044.72 | $18,528.64 | $280,108.31 |
| 6 | $9,650.46 | $17,922.90 | $270,457.86 |
| 7 | $10,296.77 | $17,276.59 | $260,161.09 |
| 8 | $10,986.36 | $16,587.00 | $249,174.73 |
| 9 | $11,722.14 | $15,851.22 | $237,452.59 |
| 10 | $12,507.19 | $15,066.17 | $224,945.40 |
| 11 | $13,344.82 | $14,228.54 | $211,600.58 |
| 12 | $14,238.55 | $13,334.81 | $197,362.03 |
| 13 | $15,192.13 | $12,381.23 | $182,169.90 |
| 14 | $16,209.57 | $11,363.79 | $165,960.33 |
| 15 | $17,295.16 | $10,278.20 | $148,665.17 |
| 16 | $18,453.45 | $9,119.91 | $130,211.72 |
| 17 | $19,689.31 | $7,884.05 | $110,522.41 |
| 18 | $21,007.94 | $6,565.42 | $89,514.47 |
| 19 | $22,414.88 | $5,158.48 | $67,099.59 |
| 20 | $23,916.05 | $3,657.31 | $43,183.54 |
| 21 | $25,517.75 | $2,055.61 | $17,665.79 |
| 22 | $17,665.79 | $427.89 | $0.00 |
Compare $100, $200 and $500 extra each month
These examples use a $320,000 remaining balance, a fixed 6.5% annual interest rate, 27 years remaining and no upfront lump sum. The modeled regular principal-and-interest payment is $2,097.78; each extra amount starts with the next monthly payment and continues until payoff.
| Extra per month | Time remaining | Time saved | Interest saved |
|---|---|---|---|
| $100 | 24 years | 3 years | $47,298.70 |
| $200 | 21 years 8 months | 5 years 4 months | $82,542.89 |
| $500 | 17 years | 10 years | $150,543.68 |
The examples use the same calculation as the tool. They exclude escrow, mortgage insurance, fees, penalties and rate changes. Enter your own remaining balance and term to compare your loan.
One extra payment a year or biweekly payments?
Paying half a monthly amount every two weeks produces 26 half-payments in a year, equal to 13 monthly payments. Paying half twice a month produces only 12 monthly payments. Check your servicer's fees, posting schedule and prepayment terms before choosing a plan; the CFPB explains the distinction.
This tool applies extra principal monthly and a lump sum immediately. To model an annual extra-payment budget spread evenly through the year, divide that budget by 12 and enter it as the extra monthly amount. That is not the same interest schedule as a year-end lump sum or a servicer crediting payments every two weeks. Confirm how and when extra money reaches principal.
How the payoff is calculated
scheduled payment = balance × r ÷ (1 − (1 + r)^−months), r = rate ÷ 12
each month: interest = balance × r
principal = payment + extra − interest
balance = balance − principal
The lump sum reduces starting principal before the first month’s interest.Both schedules use the same derived regular payment. Years are converted to the nearest whole month. The initial lump sum is separate from the principal paid by later installments in the table. Interest retains precision until display, and the final installment is adjusted to the amount due. Your actual contractual payment and servicer posting rules may differ.
Frequently asked questions
How much does an extra $200 a month save on a mortgage?
On a $2,097.78-a-month balance of $320,000 at 6.5% with 27 years left, $200 extra each month pays the loan off 5 years 4 months sooner and saves about $82,542.89 in interest. Enter your own loan above.
Is it better to pay extra monthly or make one lump sum?
Dollar for dollar, earlier is better: a lump sum today saves more interest than the same amount spread over years, because interest accrues on the outstanding balance every month. The calculator lets you combine both.
Does this decide whether prepaying is better than investing?
No. It compares two loan-payment schedules. Liquidity needs, taxes, investment outcomes, penalties and other obligations are outside the model.
Do extra payments change my monthly payment?
This model keeps the regular principal-and-interest payment unchanged, so extra principal shortens repayment. Recasting or another change in loan terms can change the required payment; check your servicer’s policy.
Do I need to tell my lender to apply extra payments to principal?
Yes. Mark extra amounts "apply to principal" so they are not treated as a prepayment of next month's installment. The CFPB explains the difference.
Related calculators
Sources and updates
Methods and figures reviewed on . Provider rates and terms can change; check the linked source and your own account terms.
- CFPB, biweekly payments and annual extra principal
- CFPB, mortgage servicing and extra principal payments
- CFPB, What is amortization and how does it work?
This calculator gives estimates for information only and is not tax, legal or financial advice. Actual outcomes depend on the assumptions, timing, taxes, fees and terms that apply to you. See how we calculate.