How to calculate a loan or mortgage payment
- Enter the loan amount, the yearly interest rate, and the term in years or months.
- Optionally add an extra monthly payment to see how much sooner you would finish and how much interest you would save.
- Read the monthly payment and total interest, then browse the schedule by year or by month.
- Use "Download CSV" to open the full month-by-month schedule in a spreadsheet.
Terms up to 100 years are supported. The calculator assumes equal monthly payments at a fixed rate, with interest charged each month on the remaining balance.
Questions
Is my loan information stored or sent anywhere?
No. The figures are worked out in your browser while you type. Nothing is uploaded, saved, or tracked.
How is the monthly payment calculated?
The calculator uses the standard fixed-rate formula: payment = P × r ÷ (1 − (1 + r)^−n), where P is the amount, r is the monthly rate (the yearly rate divided by 12), and n is the number of monthly payments. At a rate of 0% the payment is simply the amount divided by the number of months.
What does an extra payment do?
Every extra amount goes straight to the balance, so the next month charges less interest. The loan ends sooner and total interest drops. The page shows how much interest and how many months you would save compared with no extra payments.
Why does most of my early payment go to interest?
Interest is charged on the remaining balance, which is highest at the start. As the balance falls, the interest part of each equal payment shrinks and the principal part grows. The chart and schedule show this shift year by year.
Does this include taxes, insurance, or fees?
No. It covers principal and interest on a fixed-rate loan only. Property tax, insurance, fees, and variable rates are not included, so real payments can differ. This page is for learning and rough planning, not financial advice.
Credits
Built by OneTooling using standard browser features. No third-party code runs on your data.