How this loan calculator works
Enter how much you're borrowing, the interest rate (APR), the term, and any extra monthly payment. The calculator works out your fixed monthly payment, the total interest over the life of the loan, and a year-by-year amortization schedule showing how the split between principal and interest changes over time.
The formula
where M is the monthly payment, P the amount borrowed, r the monthly rate (APR ÷ 12) and n the number of months. Each month, interest is charged on the remaining balance first and the rest of your payment reduces the principal — which is why early payments are mostly interest.
Works for any loan
Use it for a car loan, personal loan, or student loan. For a home loan specifically, the mortgage payoff calculator focuses on how extra payments shorten the term. For credit card debt, the credit card payoff calculator works the same way without a fixed term. If you have multiple debts, compare snowball vs avalanche strategies with the debt payoff calculator. To see how savings grow instead of debt shrinking, try the compound interest calculator.
Frequently asked questions
- How is my monthly loan payment calculated?
- With the amortization formula above — each payment covers that month's interest first, then principal.
- How much total interest will I pay?
- The sum of every month's interest — shown above. A higher rate or longer term increases it.
- Do extra payments save money?
- Yes — they go straight to principal, cutting interest and the payoff time. Add an extra amount to see.
- Is this calculator free?
- Yes, free, no sign-up, runs entirely in your browser.