Loan Calculator

This calculator handles any amortising instalment loan — personal, auto, student, or business. They all use the same arithmetic: a fixed payment, part interest on the outstanding balance and part principal repayment, sized so the balance reaches exactly zero on the final scheduled payment.

Three inputs determine everything. The amount borrowed sets the scale. The rate sets how expensive the borrowing is. The term sets how long you are exposed to that rate — and it is the input people misuse most. Extending a term always lowers the monthly payment, which makes it feel like the cheaper option, while almost always raising the total amount repaid. A longer term means the balance stays large for longer, and interest accrues on that balance the whole time. Compare the total interest figure, not just the monthly payment.

Watch for the distinction between the quoted interest rate and the APR. The APR folds in origination fees, points, and other required charges, which is what makes it the only fair basis for comparing two offers. A loan with a lower headline rate and a large origination fee can easily cost more than one with a higher rate and no fee.

Also check whether a loan carries a prepayment penalty. Most consumer instalment loans in the US do not, but some do, and it changes the value of paying early. If there is no penalty, any extra payment goes straight against principal and removes all the future interest that principal would have carried. Everything runs in your browser — no login, no upload, and no figure you enter leaves the page.