Amortization Calculator
See a full month-by-month breakdown of any fixed-rate loan's principal and interest.
Enter your numbers and select Calculate to see results.
About This Calculator
This amortization calculator works for any fixed-rate loan — mortgage, auto, personal, or student loan. Enter the loan amount, interest rate, and term to see your monthly payment and a complete schedule showing exactly how much of each payment goes to principal versus interest, and how your balance declines over time.
How This Is Calculated
Interestₙ = Balanceₙ₋₁ × (rate ÷ 12); Principalₙ = Payment − Interestₙ
- Interestₙ
- — Interest portion of payment n
- Balanceₙ₋₁
- — Remaining balance before payment n
- Principalₙ
- — Principal portion of payment n
On a $250,000 loan at 6% for 30 years, the first payment of about $1,499 splits into roughly $1,250 interest and $249 principal — that ratio flips gradually over the loan's life.
Assumptions
- Fixed interest rate for the full term.
- Standard monthly compounding, no extra payments.
Frequently Asked Questions
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Last updated January 15, 2026. Results are estimates for informational purposes only — read our disclaimer.