Amortization schedule calculator

An amortization schedule is the month-by-month plan for paying off a fixed-rate loan — a mortgage, car loan, or personal loan. Each payment is the same size, but the split between interest and principal changes every month. This calculator shows your monthly payment, the total interest you'll pay, how long the loan takes to clear, and a year-by-year breakdown so you can see exactly where your money goes.

How to read each row of the schedule

Every row is one payment, and four numbers matter. The payment stays the same the whole way through. Inside it, the interest column is the rate applied to whatever you still owe that month, and the principal column is the leftover that actually reduces your balance. The balance column is what you'll owe after the payment clears. The only number that moves your loan forward is principal — interest is just the cost of borrowing the balance for one more month.

Take a $200,000 loan at 6% over 30 years. The payment is $1,199.10. In the very first month, interest is the balance times the monthly rate: $200,000 × (6% ÷ 12) = $1,000. That leaves only $199.10 to pay down principal. So after a full $1,199 payment, you still owe $199,800.90. That single row explains the complaint almost everyone has in year one: it feels like the balance barely budges.

Why early payments are nearly all interest

Interest is charged on the balance you carry, and the balance is at its highest the day the loan begins. With most of the principal still outstanding, the interest slice of each payment is large and the principal slice is small. Each month you knock the balance down a little, so next month's interest is slightly lower and a few more dollars fall through to principal. The shift is slow at first and then accelerates, because every dollar of principal you retire permanently removes the interest it would have generated.

The moment the principal portion of a payment finally exceeds the interest portion is the tipping point of the loan. On that $200,000 loan it doesn't arrive until month 223 — about 19 years in. For the first 18-plus years, more than half of every payment is interest; only after the tipping point does the balance start dropping in earnest. That long front-loaded stretch is exactly why selling or refinancing early gives back so little equity.

How an extra payment moves the schedule

An extra amount each month skips the interest column entirely and lands straight on principal. Because it shrinks the balance, every future month is charged interest on a smaller number, which frees up more of the regular payment for principal too. The effect compounds.

On the same $200,000 loan, adding $200 a month pays it off in 252 months instead of 360 — nine years early — and drops total interest from $231,676 to $151,876, a saving of about $79,800. The tipping point where principal overtakes interest moves up from month 223 all the way to month 114. Extra payments work hardest the earlier you make them, because a dollar applied in year one avoids interest for the entire remaining term, while the same dollar in the final year saves almost nothing.

One thing the schedule will not show you: prepaying does not lower the payment you owe each month, only the number of months you owe it for. Our guide on overpaying by $100 a month works through what that extra is really worth at different rates, and when holding the cash beats sending it.

Good to know

• This covers principal and interest only.
• Taxes, insurance, PMI, and fees aren't included, so a real mortgage bill is usually higher.
• The rate you enter is treated as a steady APR for the whole term. Adjustable-rate loans will diverge once the rate resets.
• The schedule groups payments by year so the table stays readable; the totals still reflect month-by-month interest.

Frequently asked questions

Last reviewed June 2026. This tool is for education, not financial advice.