Pay Off Mortgage Calculator: See How Extra Payments Change Your Payoff Date
This pay off mortgage calculator compares your current mortgage schedule with a schedule that includes extra principal payments. Enter your remaining balance, rate, remaining term, and monthly payment, then add an extra monthly amount or a one-time payment to see the new payoff date, the time saved, and the interest you could avoid.
Mortgage Payoff Calculator
Paid off
Under these assumptions, adding $300.00 extra a month could pay off the mortgage in October 2047 instead of October 2056, 9 years sooner, and save an estimated $119,701.38 in interest.
- Current payoff date
- New payoff date
- Total interest without extra payments
- Total interest with extra payments
- Interest saved
- Total paid with extra payments
Current payoff
With $300.00 extra a month
Time saved
Balance Over Time
With extra payments (solid)Current schedule (dashed)
| Year | Interest Paid | Principal Paid | Ending Balance |
|---|---|---|---|
| 1 | $17,799.12 | $7,384.68 | $292,615.32 |
| 2 | $17,343.64 | $7,840.16 | $284,775.16 |
| 3 | $16,860.08 | $8,323.72 | $276,451.44 |
| 4 | $16,346.69 | $8,837.11 | $267,614.33 |
| 5 | $15,801.64 | $9,382.16 | $258,232.17 |
| 6 | $15,222.97 | $9,960.83 | $248,271.34 |
| 7 | $14,608.60 | $10,575.20 | $237,696.14 |
| 8 | $13,956.35 | $11,227.45 | $226,468.69 |
| 9 | $13,263.87 | $11,919.93 | $214,548.76 |
| 10 | $12,528.67 | $12,655.13 | $201,893.63 |
| 11 | $11,748.13 | $13,435.67 | $188,457.96 |
| 12 | $10,919.45 | $14,264.35 | $174,193.60 |
| 13 | $10,039.65 | $15,144.15 | $159,049.46 |
| 14 | $9,105.59 | $16,078.21 | $142,971.25 |
| 15 | $8,113.93 | $17,069.87 | $125,901.38 |
| 16 | $7,061.09 | $18,122.71 | $107,778.67 |
| 17 | $5,943.32 | $19,240.48 | $88,538.20 |
| 18 | $4,756.61 | $20,427.19 | $68,111.01 |
| 19 | $3,496.71 | $21,687.09 | $46,423.92 |
| 20 | $2,159.10 | $23,024.70 | $23,399.22 |
| 21 | $738.98 | $23,399.22 | $0.00 |
Assumptions
- The interest rate is fixed for the rest of the loan and interest is charged monthly at the APR divided by 12.
- Payments cover principal and interest only; escrow for property taxes, insurance, and mortgage insurance is excluded.
- Every extra payment goes straight to principal, and the loan has no prepayment penalty.
- Dates count from next month, the first payment after today, and assume every payment is made on time.
- Taxes, including any mortgage interest deduction, are not included.
Educational estimate only. This calculator uses the assumptions you enter to illustrate a possible financial outcome. It does not predict future investment performance, interest rates, inflation, taxes, market prices, or financial results. Actual outcomes may differ.
How the Mortgage Payoff Calculator Works
A fixed-rate mortgage charges interest each month on the remaining balance, at the annual rate divided by 12. Each payment covers that month's interest first, and the rest reduces the principal. The scheduled payment that pays off a balance over a set number of months is:
Payment = Balance × r ÷ (1 − (1 + r)^−n)
Here r is the monthly rate and n is the number of remaining payments. The calculator then steps through the loan month by month, twice: once with your current payment, and once with the extra payments added. Extra amounts go straight to principal, so less interest builds up in every later month, and the balance reaches zero sooner.
A Worked Example
Take a $300,000 balance at 6% with 30 years left. The scheduled principal-and-interest payment is about $1,798.65. On that schedule, total interest comes to about $347,515.58 over 360 payments.
Adding $300 a month to principal changes the picture. The balance is paid off after 252 payments instead of 360, nine years sooner, and total interest falls to about $227,814.20, a saving of about $119,701.38. Counting from October 2026, the payoff date moves from October 2056 to October 2047. These are Fin Loom calculations from the same engine that runs the calculator.
What the Results Mean
Time saved is the difference between the two payoff dates. Interest saved is the total interest on the current schedule minus the total interest with extra payments. The comparison cards show both payoff dates side by side, and the chart traces both balances year by year. The table lists the interest and principal paid each year on the faster schedule, so you can see the share of each payment going to principal grow over time.
If the payment you enter is below the scheduled payment for your term, the calculator shows how long the current schedule would actually run. If the payment does not even cover one month's interest, it flags the field, because that balance would never be paid off.
Paying Extra vs Using the Money Elsewhere
Extra mortgage payments earn a return equal to the interest you avoid, which is known in advance for a fixed-rate loan. The same money could instead build an emergency fund or be invested, which can offer more flexibility or a different expected return along with different risks. Saving vs investing explains how time horizon and liquidity shape that kind of decision. This calculator shows the interest side of the tradeoff only.
Limits of a Mortgage Payoff Calculator
The calculator assumes a fixed rate, on-time payments, and no prepayment penalty. It excludes escrow for property taxes, homeowners insurance, and mortgage insurance, and it does not account for any mortgage interest tax deduction. Adjustable-rate loans, recasts, and refinancing follow different rules, and your servicer's statement is the authoritative source for your balance and payoff amount.
More Fin Loom Calculators
This tool is part of Fin Loom's set of financial calculators and reference tools, which covers inflation, compound interest, investment growth, dividends, withdrawals, taxes, and stock trades.
Frequently Asked Questions
Does Paying Extra Each Month Shorten a Mortgage?
Yes, if the extra amount goes to principal. Each extra dollar lowers the balance that later interest is charged on, so the loan is paid off sooner.
Should the Payment Include Taxes and Insurance?
No. Enter only principal and interest. Escrow amounts for property taxes and insurance do not reduce the loan balance.
Is a One-Time Payment Worth Modeling?
It can be. A lump sum, such as a bonus, lowers the balance immediately. The calculator lets you choose the month it is applied to see its effect.