Amortization Schedule Calculator

How the calculation works

For principal P, periodic interest r and N payments: payment = P × r / [1 − (1 + r)^−N]. When r = 0, payment = P/N. Period interest = opening balance × r; principal repaid = payment − interest. Extra payments reduce principal and the final payment is capped at the amount owed.

Worked example

A $12,000 loan over one year at zero interest with monthly payments is $1,000 per month. Add $200 principal each month and repayment finishes in ten payments, with $12,000 repaid and no interest.

Assumptions and limitations

The entered annual rate is nominal and divided by 12, 26 or 52 payment periods. Term rounds to a whole period. Monthly due dates preserve the original day where possible, clamping to shorter month ends; fortnightly and weekly dates advance by 14 and 7 days. Interest does not round each period, while display and CSV currency values round to two decimal places.

This table is a mathematical estimate, not a lender statement. Actual accrual, holiday adjustments, rounding, fees and local compounding conventions can differ. Export includes only the schedule you requested; nothing is uploaded. Periodic accelerated-mortgage conventions are not implied by choosing weekly payments.

Sources and editorial responsibility

Maintained by Renvoro Pty Ltd. These mathematical estimates do not provide financial, tax, legal or investment advice.

• CFPB: principal, interest and amortization