Loan Amortization Calculator

How to use Loan Amortization Calculator

A fixed-payment amortizing model applies one twelfth of the nominal annual rate each month. Each payment covers interest first and then reduces principal.

1. Enter loan principal, nominal annual interest rate (%), number of monthly payments.
2. Check that the input follows the stated limits and uses consistent units.
3. Run the calculator, review the result, then copy or download it.

Good to know

• 1–1,200 monthly payments and a nonnegative nominal rate up to 1,000%. No fees, insurance, tax, extra payments, or day-based interest. Internal amounts are unrounded; displayed schedule values are estimates.
• Decimal inputs have at most 120 characters and magnitude from 1e-100 to 1e15, or zero. Floating-point results are rounded to 12 significant digits; extreme derived results may underflow or be rejected. Exact integer results are identified separately.
• Educational estimate with user-entered assumptions, not a quote or financial/tax advice. Rates are hypothetical, fixed, and not fetched. Fees, taxes, inflation, payment-day conventions, and currency rules are excluded unless explicitly entered.