Amortization Schedule Calculator

Amortization schedule calculator turns a principal, a yearly percent, and a term in years into a monthly payment. 300,000 at 6.5 percent for 30 years displays 1,896.2.

The opening numbers

The payment is the standard fixed payment for the monthly rate and the month count. When the rate is 0, the payment is the principal divided by the number of months. 300,000 at 6.5 percent for 30 years is a payment of 1,896.2, a total paid of 682,633.47, and interest of 382,633.47. The schedule line says it is showing the first 12 of 360 months. Month 1 pays 1,896.2, of which interest is 1,625 and principal is 271.2, leaving a balance of 299,728.8. The fields are Principal, Annual rate %, Term (years), and Show first N months. The button reads Calculate. October 2026 is when this payment formula was checked.

What the rows leave out

The totals cover every month, even when the list is short. The row count you type is clamped between 1 and 60, and it cannot exceed the term. The opening value is 12. A 0 percent rate on 1,200 for 1 year pays 100 a month, interest is 0, and month 1 leaves a balance of 1,100. A principal of 0 throws Principal and years must be positive. A negative rate throws Rate cannot be negative. A blank principal box stops on Enter a valid number before a payment is drawn. Fees, insurance, and a changing rate are not in the formula. The payment does not add them. A second rate is not blended.

How to check month 1

Leave 300000, 6.5, 30, and 12, then press Calculate. The payment line should be 1,896.2. The interest on month 1 should be 1,625. The balance should be 299,728.8. Change the rate to 0, the principal to 1200, and the years to 1. The payment should be 100 and the interest total should be 0. Change the principal to 0 and expect the positive-number error rather than a payment.

The figures stay in the tab

The payment math runs in this browser. The principal, rate, and term are not uploaded. Nothing is stored when you leave. The list is a preview of the first rows, and the three totals still cover the full term. This is planning math, not a quote from a lender. Month 12 of the opening example leaves a balance of 296,646.82. The row field opens at 12. Typing 0 is raised to 1, and typing 99 is cut to 60, before the list is built. A 0 percent rate on 1,200 for one year pays 100 each month. Interest on that run is 0, and month 1 leaves 1,100.