Every mortgage payment is split between interest and principal, and early on the split is brutally lopsided. This calculator builds the full schedule — month by month or year by year — so you can see exactly when your payments start buying the house rather than renting the money.
| Year | Principal paid | Interest paid | Ending balance |
|---|---|---|---|
| 1 | $3,659 | $23,862 | $346,341 |
| 2 | $3,918 | $23,603 | $342,423 |
| 3 | $4,195 | $23,326 | $338,227 |
| 4 | $4,492 | $23,029 | $333,736 |
| 5 | $4,809 | $22,712 | $328,927 |
| 6 | $5,149 | $22,372 | $323,778 |
| 7 | $5,513 | $22,008 | $318,264 |
| 8 | $5,903 | $21,618 | $312,362 |
| 9 | $6,320 | $21,201 | $306,041 |
| 10 | $6,767 | $20,754 | $299,275 |
| 11 | $7,245 | $20,276 | $292,029 |
| 12 | $7,757 | $19,763 | $284,272 |
| 13 | $8,306 | $19,215 | $275,966 |
| 14 | $8,893 | $18,628 | $267,073 |
| 15 | $9,522 | $17,999 | $257,551 |
| 16 | $10,195 | $17,326 | $247,357 |
| 17 | $10,915 | $16,605 | $236,441 |
| 18 | $11,687 | $15,834 | $224,754 |
| 19 | $12,513 | $15,008 | $212,241 |
| 20 | $13,398 | $14,123 | $198,843 |
| 21 | $14,345 | $13,176 | $184,498 |
| 22 | $15,359 | $12,162 | $169,139 |
| 23 | $16,445 | $11,076 | $152,694 |
| 24 | $17,607 | $9,914 | $135,086 |
| 25 | $18,852 | $8,669 | $116,234 |
| 26 | $20,185 | $7,336 | $96,050 |
| 27 | $21,612 | $5,909 | $74,438 |
| 28 | $23,139 | $4,381 | $51,298 |
| 29 | $24,775 | $2,746 | $26,523 |
| 30 | $26,523 | $994 | $0 |
30 years — download the CSV for the full month-by-month table.
| Year | Principal | Interest | Balance |
|---|---|---|---|
| 1 | $3,659 | $23,862 | $346,341 |
| 2 | $3,918 | $23,603 | $342,423 |
| 3 | $4,195 | $23,326 | $338,227 |
| 4 | $4,492 | $23,029 | $333,736 |
| 5 | $4,809 | $22,712 | $328,927 |
| 6 | $5,149 | $22,372 | $323,778 |
| 7 | $5,513 | $22,008 | $318,264 |
| 8 | $5,903 | $21,618 | $312,362 |
| 9 | $6,320 | $21,201 | $306,041 |
| 10 | $6,767 | $20,754 | $299,275 |
| 11 | $7,245 | $20,276 | $292,029 |
| 12 | $7,757 | $19,763 | $284,272 |
| 13 | $8,306 | $19,215 | $275,966 |
| 14 | $8,893 | $18,628 | $267,073 |
| 15 | $9,522 | $17,999 | $257,551 |
| 16 | $10,195 | $17,326 | $247,357 |
| 17 | $10,915 | $16,605 | $236,441 |
| 18 | $11,687 | $15,834 | $224,754 |
| 19 | $12,513 | $15,008 | $212,241 |
| 20 | $13,398 | $14,123 | $198,843 |
| 21 | $14,345 | $13,176 | $184,498 |
| 22 | $15,359 | $12,162 | $169,139 |
| 23 | $16,445 | $11,076 | $152,694 |
| 24 | $17,607 | $9,914 | $135,086 |
| 25 | $18,852 | $8,669 | $116,234 |
| 26 | $20,185 | $7,336 | $96,050 |
| 27 | $21,612 | $5,909 | $74,438 |
| 28 | $23,139 | $4,381 | $51,298 |
| 29 | $24,775 | $2,746 | $26,523 |
| 30 | $26,523 | $994 | $0 |
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A table showing every payment over the life of a loan, split into interest and principal, with the remaining balance after each one. It reveals exactly when your payments start building equity rather than mostly covering interest.
Interest is charged on the outstanding balance, which is at its largest on day one. On a typical 30-year loan the first payment is roughly 75% interest. The split shifts gradually, and principal only overtakes interest around year 18.
With the standard annuity formula: M = P·r / (1 − (1+r)⁻ⁿ), where P is the loan amount, r the monthly rate (annual rate ÷ 12), and n the number of payments. Each period charges interest on the current balance and applies the remainder to principal.
Much later than halfway through the term. On a 30-year loan at typical rates you do not pay off half the principal until around year 19 or 20 — the reason extra principal payments early are so much more valuable than late ones.
Yes. The CSV export contains every month of the schedule with payment, principal, interest, balance, and cumulative interest, so you can open it in a spreadsheet and model your own scenarios.
Sources: Standard amortization (annuity) formula; Consumer Financial Protection Bureau — understanding your mortgage.
Estimates for educational purposes only — not a loan offer, financial advice, or a commitment to lend. Actual rates, payments, and terms vary by lender and creditworthiness.