See how extra payments can shorten your loan and save thousands in interest
Original vs accelerated schedule side by side
| Month | Payment | Principal | Interest | Orig. Balance | New Balance |
|---|---|---|---|---|---|
| 1(Yr 1) | $2,223 | $489 | $1,733 | $319,711 | $319,511 |
| 2(Yr 1) | $2,223 | $492 | $1,731 | $319,420 | $319,019 |
| 3(Yr 1) | $2,223 | $495 | $1,728 | $319,127 | $318,524 |
| 4(Yr 1) | $2,223 | $497 | $1,725 | $318,833 | $318,027 |
| 5(Yr 1) | $2,223 | $500 | $1,723 | $318,538 | $317,527 |
| 6(Yr 1) | $2,223 | $503 | $1,720 | $318,241 | $317,024 |
| 7(Yr 1) | $2,223 | $505 | $1,717 | $317,942 | $316,519 |
| 8(Yr 1) | $2,223 | $508 | $1,714 | $317,641 | $316,011 |
| 9(Yr 1) | $2,223 | $511 | $1,712 | $317,339 | $315,500 |
| 10(Yr 1) | $2,223 | $514 | $1,709 | $317,036 | $314,986 |
| 11(Yr 1) | $2,223 | $516 | $1,706 | $316,730 | $314,470 |
| 12(Yr 1) | $2,223 | $519 | $1,703 | $316,423 | $313,950 |
| 13(Yr 2) | $2,223 | $522 | $1,701 | $316,115 | $313,428 |
| 14(Yr 2) | $2,223 | $525 | $1,698 | $315,804 | $312,904 |
| 15(Yr 2) | $2,223 | $528 | $1,695 | $315,492 | $312,376 |
| 16(Yr 2) | $2,223 | $531 | $1,692 | $315,179 | $311,845 |
| 17(Yr 2) | $2,223 | $533 | $1,689 | $314,863 | $311,312 |
| 18(Yr 2) | $2,223 | $536 | $1,686 | $314,546 | $310,775 |
| 19(Yr 2) | $2,223 | $539 | $1,683 | $314,227 | $310,236 |
| 20(Yr 2) | $2,223 | $542 | $1,680 | $313,907 | $309,694 |
| 21(Yr 2) | $2,223 | $545 | $1,678 | $313,584 | $309,149 |
| 22(Yr 2) | $2,223 | $548 | $1,675 | $313,260 | $308,601 |
| 23(Yr 2) | $2,223 | $551 | $1,672 | $312,935 | $308,050 |
| 24(Yr 2) | $2,223 | $554 | $1,669 | $312,607 | $307,496 |
This calculator shows what happens when you pay more than the required mortgage payment — monthly extras, annual lump sums, or both. It recomputes the amortization schedule and reports the years shaved off the loan and the total interest saved.
Because interest accrues on the remaining balance, every extra dollar of principal eliminates all the future interest that dollar would have generated. Extra payments made early in the loan, when balances are largest, have the biggest effect.
Dollar for dollar, earlier is better: twelve $100 monthly extras beat a single $1,200 payment at year-end, because each dollar starts saving interest sooner. Practically, the difference is small — the habit you'll sustain matters more.
Paying extra earns a guaranteed, tax-free return equal to your mortgage rate. Investing has historically returned more over long horizons but with risk. Many people split the difference after capturing any employer 401(k) match and paying off higher-rate debt first. A licensed advisor can weigh your specific situation.
No — they shorten the loan instead. Your required payment stays fixed, but the final payoff date moves earlier. If you want a lower required payment after a big principal reduction, ask your lender about recasting.
Interest each month equals the remaining balance times the monthly rate. Extra principal permanently lowers that balance, so every subsequent month charges less interest — and those savings compound across the remaining life of the loan.
Small extra payments on your mortgage can shave years off your loan and save tens of thousands in interest. Here's the math.