Mortgage Calculator
Loan amount, interest rate and term in; monthly payment, total interest and a year-by-year balance out. The formula is shown, not hidden.
Example — $400,000 at 6% for 30 years$2,398.20 per month
How we got it — the example, step by step
- Monthly rate: 6% ÷ 12 = 0.5% per month. Number of payments: 30 × 12 = 360.
- Payment formula: P × r ÷ (1 − (1 + r)^−n) = 400,000 × 0.005 ÷ (1 − 1.005^−360) = $2,398.20.
- At $2,398.20 a month for 360 months, the total repaid is $863,352.76 — so the interest part is $863,352.76 − $400,000 = $463,352.76.
Check it backwards
The year-by-year table is built month by month with this payment — interest added, payment subtracted — and reaches $0.00 exactly at payment 360.
Questions people also ask
What is not in this number?
Property tax, home insurance, mortgage insurance and fees. Lenders bundle some of those into the real monthly bill, so your actual payment will be higher than this principal-and-interest figure.
Why is so much of the payment interest at first?
Interest is charged on the balance, and the balance is biggest at the start. Early payments are mostly interest; the balance — and so the interest — shrinks every month.