Mortgage Payoff Calculator
See how much time and interest you save by adding extra principal to your mortgage payment each month.
Want to understand the concept, not just the number? Read Where Your Mortgage Payment Goes .
| Year | Principal paid | Interest paid | Balance |
|---|---|---|---|
| 1 | $8,180 | $25,759 | $391,820 |
| 2 | $8,728 | $25,211 | $383,092 |
| 3 | $9,312 | $24,627 | $373,779 |
| 4 | $9,936 | $24,003 | $363,843 |
| 5 | $10,602 | $23,338 | $353,242 |
| 6 | $11,312 | $22,628 | $341,930 |
| 7 | $12,069 | $21,870 | $329,861 |
| 8 | $12,877 | $21,062 | $316,984 |
| 9 | $13,740 | $20,199 | $303,244 |
| 10 | $14,660 | $19,279 | $288,584 |
| 11 | $15,642 | $18,297 | $272,942 |
| 12 | $16,689 | $17,250 | $256,252 |
| 13 | $17,807 | $16,132 | $238,445 |
| 14 | $19,000 | $14,940 | $219,445 |
| 15 | $20,272 | $13,667 | $199,173 |
| 16 | $21,630 | $12,309 | $177,543 |
| 17 | $23,078 | $10,861 | $154,465 |
| 18 | $24,624 | $9,315 | $129,841 |
| 19 | $26,273 | $7,666 | $103,568 |
| 20 | $28,033 | $5,907 | $75,535 |
| 21 | $29,910 | $4,029 | $45,625 |
| 22 | $31,913 | $2,026 | $13,711 |
| 23 | $13,711 | $221 | $0 |
How it's calculated
The loan is simulated month by month with your extra principal applied on top of the normal payment, then compared against the same loan with no extra. The difference between the two is the interest and time you save.
Extra principal is powerful because every dollar you pay early stops accruing interest for the rest of the loan. On a $400,000 loan at 6.5% over 30 years, adding just $300 a month pays it off more than 7 years early and saves $149,581 in interest.
The earlier in the loan you add extra payments, the bigger the effect, since there is more balance and more remaining time for the savings to build. Even small, steady extra amounts add up to years off the loan.
Assumptions
- Extra payments go entirely to principal and start with the first payment.
- Savings are measured against the same loan with no extra payment.
Last updated: 2026-08-07
These assumptions follow our general methodology.
Frequently asked questions
Is paying down the mortgage better than investing?
It depends on your rate versus expected investment returns and your appetite for risk. Paying off debt is a guaranteed return equal to the rate, which is attractive when mortgage rates are high.
Does a one-time extra payment help too?
Yes. Any extra principal reduces the balance that interest is charged on. A lump sum early in the loan can save a surprising amount, though a steady monthly extra usually saves more over time.
Should I refinance or just pay extra?
They solve different problems. Refinancing lowers your rate, while extra payments shorten the loan at your current rate. If rates have dropped a lot, refinancing may help, but paying extra always cuts interest without any closing costs.