Estimate payoff timing with optional extra principal and review monthly and annual repayment breakdowns.
Repayment Calculator
Repayment Schedule (First 24 Payments)
| # | Month | Payment | Principal | Interest | Extra Principal | Ending Balance |
|---|---|---|---|---|---|---|
| 1 | Jun 2026 | $2,919 | $387 | $2,531 | $0 | $449,613 |
| 2 | Jul 2026 | $2,919 | $390 | $2,529 | $0 | $449,223 |
| 3 | Aug 2026 | $2,919 | $392 | $2,527 | $0 | $448,831 |
| 4 | Sep 2026 | $2,919 | $394 | $2,525 | $0 | $448,437 |
| 5 | Oct 2026 | $2,919 | $396 | $2,522 | $0 | $448,041 |
| 6 | Nov 2026 | $2,919 | $398 | $2,520 | $0 | $447,642 |
| 7 | Dec 2026 | $2,919 | $401 | $2,518 | $0 | $447,242 |
| 8 | Jan 2027 | $2,919 | $403 | $2,516 | $0 | $446,839 |
| 9 | Feb 2027 | $2,919 | $405 | $2,513 | $0 | $446,434 |
| 10 | Mar 2027 | $2,919 | $408 | $2,511 | $0 | $446,026 |
| 11 | Apr 2027 | $2,919 | $410 | $2,509 | $0 | $445,616 |
| 12 | May 2027 | $2,919 | $412 | $2,507 | $0 | $445,204 |
| 13 | Jun 2027 | $2,919 | $414 | $2,504 | $0 | $444,790 |
| 14 | Jul 2027 | $2,919 | $417 | $2,502 | $0 | $444,373 |
| 15 | Aug 2027 | $2,919 | $419 | $2,500 | $0 | $443,954 |
| 16 | Sep 2027 | $2,919 | $421 | $2,497 | $0 | $443,532 |
| 17 | Oct 2027 | $2,919 | $424 | $2,495 | $0 | $443,109 |
| 18 | Nov 2027 | $2,919 | $426 | $2,492 | $0 | $442,682 |
| 19 | Dec 2027 | $2,919 | $429 | $2,490 | $0 | $442,254 |
| 20 | Jan 2028 | $2,919 | $431 | $2,488 | $0 | $441,823 |
| 21 | Feb 2028 | $2,919 | $433 | $2,485 | $0 | $441,389 |
| 22 | Mar 2028 | $2,919 | $436 | $2,483 | $0 | $440,953 |
| 23 | Apr 2028 | $2,919 | $438 | $2,480 | $0 | $440,515 |
| 24 | May 2028 | $2,919 | $441 | $2,478 | $0 | $440,074 |
Annual Summary
| Year | Total Payment | Principal | Interest | Extra Principal | Ending Balance |
|---|---|---|---|---|---|
| 2026 | $20,431 | $2,758 | $17,673 | $0 | $447,242 |
| 2027 | $35,024 | $4,988 | $30,036 | $0 | $442,254 |
| 2028 | $35,024 | $5,335 | $29,689 | $0 | $436,919 |
| 2029 | $35,024 | $5,707 | $29,318 | $0 | $431,212 |
| 2030 | $35,024 | $6,104 | $28,920 | $0 | $425,108 |
| 2031 | $35,024 | $6,529 | $28,495 | $0 | $418,579 |
| 2032 | $35,024 | $6,984 | $28,041 | $0 | $411,595 |
| 2033 | $35,024 | $7,470 | $27,554 | $0 | $404,125 |
| 2034 | $35,024 | $7,990 | $27,034 | $0 | $396,135 |
| 2035 | $35,024 | $8,546 | $26,478 | $0 | $387,589 |
| 2036 | $35,024 | $9,141 | $25,883 | $0 | $378,447 |
| 2037 | $35,024 | $9,778 | $25,246 | $0 | $368,669 |
| 2038 | $35,024 | $10,459 | $24,566 | $0 | $358,211 |
| 2039 | $35,024 | $11,187 | $23,837 | $0 | $347,024 |
| 2040 | $35,024 | $11,966 | $23,058 | $0 | $335,058 |
| 2041 | $35,024 | $12,799 | $22,225 | $0 | $322,259 |
| 2042 | $35,024 | $13,690 | $21,334 | $0 | $308,569 |
| 2043 | $35,024 | $14,643 | $20,381 | $0 | $293,925 |
| 2044 | $35,024 | $15,663 | $19,361 | $0 | $278,262 |
| 2045 | $35,024 | $16,754 | $18,271 | $0 | $261,508 |
| 2046 | $35,024 | $17,920 | $17,104 | $0 | $243,588 |
| 2047 | $35,024 | $19,168 | $15,856 | $0 | $224,420 |
| 2048 | $35,024 | $20,503 | $14,522 | $0 | $203,918 |
| 2049 | $35,024 | $21,930 | $13,094 | $0 | $181,988 |
| 2050 | $35,024 | $23,457 | $11,567 | $0 | $158,531 |
| 2051 | $35,024 | $25,090 | $9,934 | $0 | $133,441 |
| 2052 | $35,024 | $26,837 | $8,187 | $0 | $106,603 |
| 2053 | $35,024 | $28,706 | $6,318 | $0 | $77,897 |
| 2054 | $35,024 | $30,705 | $4,320 | $0 | $47,193 |
| 2055 | $35,024 | $32,842 | $2,182 | $0 | $14,350 |
| 2056 | $14,593 | $14,350 | $243 | $0 | $0 |
How to use this calculator
Enter your loan amount, interest rate, and term. The calculator builds a full month-by-month amortization schedule showing principal paid, interest paid, and remaining balance at each payment. Add an optional extra-principal payment — flat monthly addition, lump sum at a specific month, or one-time payments at intervals — and watch the schedule recompute. The output shows total interest saved, months shaved off the loan, and a chart of remaining balance over time with and without extra payments. Use this calculator when you're trying to decide between a 30-year and 15-year term, when you're weighing extra principal vs investing the same dollars elsewhere, or when you want to map out a specific payoff strategy (e.g., payoff before retirement, before kids' college, etc.).
How the math works
Standard amortization computes each month's payment split as: interest = remaining balance × monthly rate, principal = monthly payment − interest, new balance = old balance − principal. Repeat until balance hits zero. Conceptually: early in the loan, the vast majority of each payment is interest (because the remaining balance is high) and only a small slice goes to principal. As principal pays down, the interest portion shrinks and the principal portion grows. By the midpoint of the loan, the split is roughly 50/50. In the final years, almost all of each payment is principal. Extra principal accelerates balance reduction. Adding even a modest amount each month to your scheduled payment reduces the remaining balance, which lowers the interest charged in every subsequent month — the savings compound. The calculator surfaces the exact lifetime interest savings and the months shaved off the loan for any extra-principal pattern you enter, using whatever rate you've specified.
When to use this vs the others
Use this calculator when you want to see the long-term impact of payments on a specific loan — either understanding how the standard amortization unfolds, or modeling extra-payment strategies. If you're shopping for a home and need to pick a price, the affordability calculator is the better start. If you're considering a refinance, the refinance calculator handles the rate-and-term swap math directly.
Frequently asked questions
Is paying extra principal better than investing?
Depends on the rate spread. If your mortgage is 7% and your expected after-tax investment return is 5%, extra principal wins. If your mortgage is 3% and you can earn 7% in the market, investing wins on expected value (with more risk). The calculator helps see the mortgage side; compare against your investment alternatives.
Should I make biweekly payments?
Biweekly payments effectively add one extra full payment per year (26 half-payments = 13 full payments). On a $300,000 loan at 6.5%, that saves about $77,000 in interest and pays the loan off 5 years early. Same effect can be achieved by adding 1/12 of a monthly payment to each scheduled payment — no need to actually switch to biweekly.
Are extra principal payments deductible?
No — only the interest portion of mortgage payments is deductible (subject to standard caps), and extra principal by definition reduces interest paid in subsequent months. There's no special deduction for paying extra; the benefit is the interest savings itself.
What's a recast vs extra principal?
Extra principal lowers your loan balance but doesn't change your monthly payment — you just pay off faster. A recast (also called re-amortization) is when the lender recalculates your monthly payment based on the lower balance, lowering the monthly amount over the remaining term. Most lenders allow recasts after a large lump sum payment, often for a small fee.
Should I pay off the mortgage before retirement?
Common rule of thumb: yes, if it's at all feasible — eliminating a mortgage payment dramatically reduces required retirement income. But running the numbers in this calculator helps confirm. Compare paying down the mortgage early vs putting the same dollars into tax-advantaged retirement accounts; the right answer depends on your tax bracket, mortgage rate, and expected investment returns.