Amortization Calculator

Enter any loan — mortgage, car, personal. Get the payment, watch principal overtake interest on the chart, and expand the full year-by-year schedule.

Monthly payment
Total interest
Total of all payments
Interest = principal at
Full amortization schedule (year by year)

What amortization means

An amortized loan has a fixed payment, but the payment's composition changes every month. Interest is charged on the remaining balance — big at first, shrinking as you repay. Whatever the interest does not consume goes to principal:

Each month: Interest = Balance × monthly rate · Principal = Payment − Interest

On a $250,000 loan at 6.5% for 30 years ($1,580/month), the first payment is about $1,354 interest and only $226 principal. The split doesn't reach 50/50 until well past year 15 — this is why early extra payments are so powerful and why little equity builds in the first years.

Reading the schedule like a lender

  • The crossover point (shown above): the month principal finally exceeds interest in your payment. The higher the rate, the later it comes.
  • Early years are interest years: selling or refinancing in year 3 of a 30-year mortgage means you mostly rented money, not built equity.
  • Shorter terms shift the whole curve: a 15-year loan starts at roughly a 60/40 principal-to-interest split instead of 15/85.

Test what extra payments do to this curve with the loan payoff calculator.

Frequently asked questions

What is an amortization schedule?

A table showing every payment of a loan split into interest and principal, with the running balance. It reveals that early payments are mostly interest — on a 30-year mortgage at 6.5%, about 86% of the first payment is interest.

Why is so much of my payment interest at the start?

Interest is charged on the outstanding balance, which is biggest at the start. As the balance falls, the same fixed payment covers the smaller interest and pushes more to principal — the process accelerates over time.

When does principal exceed interest in my payment?

Depends on rate and term. At 6.5% over 30 years, around year 16. At 4%, around year 12. Higher rates and longer terms push the crossover later. The calculator shows your exact month.

Does an extra payment change the schedule?

Yes — extra principal skips you forward on the schedule. Every dollar of early principal eliminates all the interest that dollar would have generated for the rest of the term.

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Last updated: 2026-07-08