Loan Calculator

A loan always costs more than the number on the contract, and this loan calculator shows exactly how much more. Enter the amount you want to borrow, the annual interest rate and the term — in months or years — and it instantly returns the fixed monthly payment, the total you will pay over the whole term, and the share of that total that is pure interest.

The math behind it is the standard annuity formula used by banks for personal loans, car loans and most consumer credit: M = P·r·(1+r)^n / ((1+r)^n − 1), where P is the principal, r the monthly rate (the annual rate divided by 12) and n the number of monthly payments. Interest-free installments are handled too — at 0% the payment is simply the principal divided by the number of months.

Beyond the headline numbers, the calculator prints a first-year amortization summary: for each of the first twelve payments it shows how much goes to principal, how much to interest, and what balance remains. Early in a loan the interest share is at its largest, so this table is the quickest way to understand why extra payments made in the first year save the most money.

Use it to sanity-check a bank's quote, to compare two offers with different rates and terms, or to see how stretching a car loan from three years to five lowers the payment but raises the total interest. Amounts are plain numbers, so it works with any currency, and every calculation happens in your browser — nothing is uploaded or stored.