Amortization Schedule Calculator
Build a complete month-by-month amortization schedule for any fixed-rate loan. See your monthly payment, how each payment splits between interest and principal, and how extra payments shorten the loan.
Monthly Payment
How It Works
Amortization is the process of paying off a loan in equal monthly payments. Each payment is split in two: the interest charged on the balance you still owe, and the principal that reduces that balance. The monthly payment is fixed by the formula M = P × r / (1 − (1 + r)−n), where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of payments. Each month, interest = balance × r, principal = payment − interest, and the new balance is the old balance minus the principal paid.
Because interest is charged on the remaining balance, early payments are mostly interest and later payments are mostly principal. That is why the balance falls slowly at first and then drops faster. Extra payments go straight to principal, which shrinks the balance sooner, cuts the interest charged in every following month, and shortens the loan.
Worked example: borrow $200,000 at 6.5% for 30 years. The monthly payment is $1,264.14, the total interest over the life of the loan is $255,088.98, and the total paid is $455,088.98. In the first month, $1,083.33 of the payment is interest and only $180.80 goes to principal. In the first year you pay $12,934.18 of interest and $2,235.45 of principal, leaving a balance of $197,764.55. Add $200 a month in extra principal payments and the loan is paid off in 20 years 10 months instead of 30, with total interest of $165,012.20 — a saving of about $90,077.
How to Use This Calculator
Enter the loan amount, the annual interest rate and the loan term in years. The calculator works out your fixed monthly payment, then builds the full schedule month by month: each row shows the payment, how much of it goes to principal, how much goes to interest, and the balance left after that payment.
Below the summary you will find two tables: a yearly summary that rolls each year's payments, principal, interest and ending balance into one row, and the complete monthly schedule from the first payment to the last. If you enter an extra monthly payment, the schedule is rebuilt with the extra amount going straight to principal, and the summary shows the time and interest saved. You can download the whole schedule as a CSV file or print it as a PDF.
Tips and Practical Advice
Read the first few rows of the schedule carefully — they explain why a loan balance falls so slowly at first. On a $200,000 loan at 6.5%, the first payment of $1,264.14 includes $1,083.33 of interest and only $180.80 of principal. The interest share shrinks as the balance falls, so the balance drops faster in the later years. That is also why extra payments made early are worth so much more than extra payments made late.
Use the schedule to answer real planning questions. Check the yearly summary to see your balance at any point — for example, how much you will still owe in five years, or when the balance drops below a round number. Compare two terms side by side: a shorter term raises the monthly payment but cuts total interest sharply, because interest has fewer months to build up.
Keep in mind that this schedule covers principal and interest on a fixed-rate loan only. A mortgage payment also includes property tax, homeowners insurance, PMI and HOA dues, which are not part of the amortization table — use the Mortgage Calculator for the full monthly payment. The figures here are estimates, not financial advice, and your lender's schedule may differ by a few cents due to rounding.
Frequently Asked Questions
What is an amortization schedule?
An amortization schedule is a table that shows every payment on a loan, month by month: how much of each payment goes to interest, how much goes to principal, and the balance left after each payment. It runs from the first payment until the loan is fully paid off.
How is the monthly payment calculated?
The monthly payment comes from the standard amortization formula: M = P x r / (1 - (1 + r)^-n), where P is the loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments. The payment stays the same every month for a fixed-rate loan.
Why is most of my early payment interest?
Interest each month is charged on the balance you still owe, which is largest at the start of the loan. On a $200,000 loan at 6.5%, the first payment of $1,264.14 includes $1,083.33 of interest and only $180.80 of principal. As the balance falls, the interest share shrinks and more of each payment builds equity.
Do extra payments really save that much interest?
Yes, because every extra dollar goes straight to principal and stops earning interest for the lender. On a $200,000 loan at 6.5% over 30 years, adding $200 a month pays the loan off in 20 years 10 months instead of 30 and saves about $90,077 in interest.
Does this schedule include taxes and insurance?
No. This schedule covers principal and interest only. A mortgage payment also includes property tax, homeowners insurance, PMI and HOA dues, which are not part of the amortization schedule. Use the Mortgage Calculator for the full monthly payment.
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