Understanding your loan payment
Three numbers drive a fixed-rate loan payment: how much you borrow, the interest rate, and the term. Together they set a single level payment that clears the debt by the final month. But the payment alone hides a lot — the lifetime interest, the effect of fees on the real cost, and how the balance burns down over time. This calculator surfaces all of it, so you can see not just what you pay each month but what the loan costs you in full.
The loan payment formula
M = P · [ i(1 + i)n ] / [ (1 + i)n − 1 ]
i = monthly rate, n = number of payments
What makes this calculator different
- True APR with fees. Most tools quote only the headline rate. We fold any origination or up-front fees in and solve for the effective APR — the only fair way to compare two offers.
- Extra-payment savings. See how much sooner you would be debt free, and how much interest you would avoid, by paying a little extra toward principal each month.
- Full amortization schedule. A payment-by-payment breakdown of principal, interest, and remaining balance shows exactly how the loan winds down.
Buying a car specifically? Theauto loan calculatoradds the pieces unique to a vehicle purchase — sales tax, a trade-in credit, and dealer fees — to give you a payment that reflects the out-the-door price rather than just the financed amount.
Frequently asked questions
How is a loan payment calculated?+
Fixed-rate loans use the amortization formula M = P · [ i(1 + i)ⁿ ] / [ (1 + i)ⁿ − 1 ], where P is the amount borrowed, i is the monthly interest rate (the annual rate divided by 12), and n is the total number of monthly payments. The formula solves for the single level payment that pays the loan off exactly by the final month. Each payment first covers the interest accrued that month, and whatever is left reduces the principal. Because the balance shrinks over time, early payments are mostly interest and later payments are mostly principal.
What is the difference between the interest rate and the APR?+
The interest rate is the cost of borrowing the principal, expressed as a percentage per year. The APR (annual percentage rate) is broader: it also folds in mandatory up-front fees, such as origination charges, to reflect the true yearly cost of the loan. Because of those fees, the APR is usually a little higher than the headline rate, and two loans with the same rate can have very different APRs. APR is the apples-to-apples figure for comparing offers, which is why this calculator computes it once you enter any fees.
How does the loan term affect my monthly payment and total interest?+
A longer term spreads the principal over more payments, so each monthly payment is lower and easier to fit in a budget. The trade-off is that you carry the debt longer and pay interest on it for more months, so the total interest over the life of the loan goes up — often substantially. A shorter term does the opposite: higher monthly payments, but far less interest paid overall. Use the term field to see both numbers move and find the balance that fits your situation.
How do extra payments help?+
When a loan has no prepayment penalty, any amount you pay above the scheduled payment goes straight to the principal. That immediately removes all the future interest that principal would otherwise have accrued, which is why even a modest extra amount each month can shorten the term by months or years. The compounding effect is largest early in the loan, when the balance — and therefore the interest — is highest. Enter an extra monthly amount to see exactly how much time and interest you would save.
What is amortization?+
Amortization is the process of paying off a loan with equal periodic payments that gradually retire the balance. Each payment is split between interest and principal, and the split shifts over time: at the start, most of the payment goes to interest, while near the end almost all of it goes to principal. An amortization schedule lists this breakdown payment by payment, showing the remaining balance after each one. This calculator generates the full schedule so you can see exactly how the loan winds down.
Disclaimer: This calculator is for educational purposes only. Your actual payment may include taxes, insurance, or other costs not modeled here, and rates and terms vary by lender and credit profile. It is not financial advice.