An amortization schedule shows every payment on a loan and how it splits between interest and paying down what you owe. Early payments are mostly interest; by the end, almost all of each payment reduces the balance. This calculator builds the full schedule for a mortgage, car or business loan, summarises it by year, and shows how much an extra monthly payment saves.
How it works
The fixed monthly payment comes from the standard formula P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where r is the monthly rate and n the number of payments. Each month, interest is the balance × r, and the rest of the payment reduces the balance.
Because interest is charged on the remaining balance, it falls every month, and the share of each payment going to principal grows. The yearly view makes this easy to see.
An extra payment each month goes entirely to principal. That lowers the balance faster, cuts future interest and ends the loan early. Check that your lender allows prepayments without a fee.
The schedule assumes a fixed rate. For variable-rate loans, it shows what happens if today's rate stays the same. Download the CSV to keep the full table.
A worked example
A $250,000 loan at 7% over 25 years costs $1,766.95 a month and $280,084.40 in total interest. In the first month, $1,458.33 of the payment is interest. Paying an extra $200 a month clears the loan in 19 years 5 months and saves $72,687.05 of interest.
Questions people ask
What is an amortization schedule?
A table of every loan payment showing how much goes to interest, how much to principal, and the balance left afterwards.
Why is most of my early payment interest?
Interest is charged on the outstanding balance, which is highest at the start. As the balance falls, the interest part shrinks and more of each payment repays the loan.
How much do extra payments save?
Often a lot, because every extra amount reduces the balance that interest is charged on for the rest of the loan. The calculator shows the exact saving and new payoff date.
Is it better to pay extra or invest the money?
Paying extra gives a guaranteed return equal to your loan's interest rate. Compare that with the after-tax return you'd realistically expect from investing, and keep an emergency fund either way.
Does this work for Islamic home finance?
For fixed-rate diminishing musharaka or ijara offers quoted with an annual profit rate, the instalment arithmetic is similar, so the schedule is a useful estimate. Confirm the exact schedule with the bank.