Amortization schedule

Reading an amortization schedule

Each row is one monthly payment. The interest column is the balance at the start of that month times the monthly rate; the principal column is whatever is left of the payment; the balance is what you still owe. Because the balance only falls, the interest part shrinks and the principal part grows every month, while the payment stays the same.

Worked example

A $200,000 mortgage at 6.5% for 30 years has a payment of $1,264.14. In the first month, interest is $200,000 × 0.065 ÷ 12 = $1,083.33, so only $180.81 reduces the balance, to $199,819.19. It takes about 18 years before more than half of each payment goes to principal.

Using the schedule

• Check the balance after a number of years, for refinancing or selling.
• See the effect of extra payments: add $200 a month to the example and the loan ends years earlier.
• Verify a lender's statement line by line.

The page computes the level monthly payment with the annuity formula, then walks through every month: interest is the current balance times the monthly rate, rounded to the cent; principal is the payment (plus any extra) minus that interest; the balance drops by the principal. The final payment covers whatever balance remains, so the schedule ends at exactly zero. Totals of interest and payments are summed from the rows. Everything runs in your browser.