This loan and mortgage calculator gives you the monthly payment for a fixed-rate loan, the total interest you will pay and how the balance goes down year after year.
How to use this calculator
- Loan amount: how much you borrow.
- Interest rate: the yearly nominal rate of the loan.
- Length: the number of years to repay.
The chart shows, for each year, how much of your payments goes to the principal and how much goes to interest. The table shows the balance left at the end of each year.
Example
A $250,000 mortgage at 3.5% over 25 years costs about $1,252 a month. Over the full term you pay about $125,500 of interest, so the total repaid is around $375,500.
How amortization works
With a fixed-rate loan, the monthly payment stays the same, but its split changes. At the start, most of the payment covers interest because the balance is high. As the balance falls, a growing share goes to the principal. This is why extra repayments early in a loan save the most interest.
The formula
Payment = L × i / (1 − (1 + i)^−n), where L is the loan amount, i the monthly rate and n the number of monthly payments.
Frequently asked questions
Are insurance and fees included?
No. Loan insurance, property taxes, arrangement fees and other costs are not included. Lenders must give you the full cost of the loan, often called the APR, before you sign.
Shorter or longer loan?
A shorter loan has higher monthly payments but costs much less interest overall. Compare 15, 20 and 25 years to see the difference.
Related calculators
- Net Worth Calculator: Add up what you own and what you owe to see your net worth.
- Inflation Calculator: What your money will be worth in the future, in today’s terms.
- Monthly Savings Calculator: How much to save each month to reach a target by a given date.
This page was written with the help of AI tools (Claude, by Anthropic). The calculator runs entirely in your browser: nothing you enter is sent or stored.