Loan Payment Calculator

Every fixed-rate, fixed-term loan uses the same amortization formula: payment = L × i ÷ (1 − (1 + i)^−n), where L is the loan amount, i the monthly rate derived from the APR, and n the number of monthly payments. A $10,000 loan at 8% APR over 36 months comes out to about $313 a month. That single formula covers a personal loan, a student loan, an auto loan or any other installment debt that charges a fixed rate and pays off in equal monthly amounts — only the numbers going in change.

A fixed-rate loan pays the same dollar amount every month, but the split between interest and principal inside that payment shifts the whole time you are paying it off. Early payments are mostly interest, because interest is charged on a large remaining balance; later payments are mostly principal, because the balance has shrunk. Two loans can show an identical payment on this page and still leave you owing very different amounts if you paid one off early — the mix, not just the total, matters for anyone thinking about paying ahead of schedule.

A higher APR raises both the payment and the total interest — there is no trade-off there. Term is where the trade-off lives: stretching the same loan over more months lowers the monthly payment, but raises the total interest, because interest keeps accruing on whatever balance remains for that much longer. The effect is often larger than it looks: doubling the term on a loan roughly halves the payment but can add far more than double the total interest, since more months means more time for interest to accrue on a balance that is paid down more slowly. The lowest monthly payment and the lowest total cost are usually two different loans.

The APR is meant to fold in most mandatory loan fees on top of the bare interest rate, which is why it is the figure regulators require lenders to disclose for comparing credit offers — use it here rather than a bare "interest rate" that might exclude fees. It is not, however, a complete picture of every possible cost: optional add-ons, late fees and how the lender actually structures the amortization can still sit outside the number. Comparing the total of payments across offers, not just the monthly figure, is the check that catches what the APR alone might not.

This is the plain-vanilla case: one fixed rate, one fixed term, equal monthly payments from the first month to the last, no fees added to the payment itself. Real loans sometimes differ — a variable rate that can change, an interest-only period before amortization starts, a balloon payment due at the end, or fees rolled into the payment — any of which changes the true cost away from what this formula shows. For loan types with their own specific quirks (an auto loan's trade-in and taxes, a mortgage's escrow and points, a personal loan's origination fee), a product-specific calculator or your lender's own amortization schedule will be more exact than this general-purpose one.