Auto loan calculator

How auto loan payments are calculated

An auto loan uses standard fixed-rate amortization. The monthly payment formula is:

P = L × (r × (1 + r)^n) / ((1 + r)^n − 1)

Where L is the loan amount, r is the monthly interest rate (annual APR ÷ 12), and n is the total number of monthly payments. The calculator above does this math for you and shows total interest paid over the life of the loan, plus a comparison of how the same loan looks at 36, 48, 60, 72, and 84 months.

Longer terms cost more — even at the same rate

A common mistake is fixating on the monthly payment. A $25,000 loan at 7.5% APR costs $501/month for 60 months ($5,061 total interest) — but only $381/month for 84 months ($7,001 interest). The longer term costs $1,940 more even though monthly is lower. The calculator's side-by-side comparison surfaces this trade-off clearly.

This is a generic calculator and does not account for sales tax, dealer fees, or registration costs. For total purchase cost including those, see our out-of-state purchase calculator and dealer vs private-party purchase guide. If you're considering refinancing an existing auto loan, see our auto loan refinance guide. For low-credit-score buyers, bad credit auto loans covers structural pricing differences.