Enter your car, loan and running costs. See the true all-in monthly cost and lifetime opportunity cost.
This calculator reveals the full amount you actually pay for a financed vehicle — sticker price plus every dollar of interest over the loan term — and compares it to buying the same car with cash or choosing a less expensive alternative. It's for anyone negotiating a car purchase who wants to see what "just $450/month" really costs over 60 or 72 months.
Car loan interest is calculated using simple amortization: Monthly Payment = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan principal, r is the monthly interest rate (APR ÷ 12), and n is the number of payments. Total interest paid = (Monthly Payment × n) − P. A $35,000 car at 7% APR over 60 months costs $41,162 total — $6,162 in interest on top of the purchase price.
Cars are the second-largest purchase most people make, and financing is the default. The average new car payment in the US hit $735/month in 2024 at an average APR of 7.1% — with average loan terms stretching to 68 months. On those terms, buyers pay roughly $8,000–$12,000 in interest per vehicle. Over a lifetime of car payments (most people buy 8–10 cars), that's $80,000–$120,000 in interest alone.