Amortization Schedule Generator
See exactly how each payment splits between interest and principal, month by month, for the full life of the loan. Results update as you type, and the link always carries your numbers.
| Month | Payment | Principal | Interest | Balance |
|---|
How this calculator works
The monthly payment comes from the standard amortization formula M = P·r / (1 − (1 + r)−n), where P is the loan amount, r is the monthly rate, and n is the number of payments. From there, the schedule walks forward one month at a time: each month's interest is the current balance times the monthly rate, the principal portion is the payment minus that interest, and the balance drops by the principal amount. The final month is adjusted so the payment exactly equals the remaining balance plus its interest — this is what corrects the floating-point rounding that would otherwise leave a few stray cents on the books.
Worked example
Borrow $25,000 at 6.5% for 5 years (60 months): the monthly payment is $489.15. Month 1 charges $135.42 in interest and $353.74 in principal; by month 60, interest has dropped to just $2.64 and principal makes up nearly the whole $489.15 payment. Total interest over the full term comes to $4,349.22, for a total paid of $29,349.22 — and the balance in the table below lands on exactly $0.00 at month 60.
Frequently asked questions
Why does the interest portion shrink every month?
Each payment is a fixed total, but interest is charged only on the balance still outstanding. Early on, the balance is large, so a bigger slice of the fixed payment covers interest and a smaller slice reduces principal. As the balance shrinks, less of the payment is needed for interest, so more flows to principal — the same fixed payment does more work over time. The full table below makes that shift visible row by row instead of asking you to take it on faith.
Can I use this for a mortgage?
Yes — the same fixed-rate amortization math applies to mortgages, auto loans, personal loans, and student loans. Enter the loan amount, annual rate, and term in years, and the schedule scales to whatever size and length of loan you're working with.
Why doesn't the balance hit exactly zero without an adjustment?
Floating-point rounding. The payment amount has more decimal places than a real payment (which is rounded to the cent), and compounding that tiny rounding difference across dozens or hundreds of months can leave a few cents of balance unaccounted for. This tool corrects the final row specifically — the last payment is set to the exact remaining balance plus that month's interest, so the schedule always ends at exactly $0.00 the way a real payoff would.
What if I want to make extra payments?
This tool generates the standard schedule for the payment amount as agreed — it doesn't model extra or lump-sum payments. If you're planning to pay a loan off faster than scheduled, the mortgage payoff calculator and debt payoff calculator on this site are built specifically for that scenario and will show you the time and interest saved.