Auto Loan Calculator
Calculate the true monthly cost of a car loan — including down payment, trade-in credit, and sales tax on the taxable amount. Also shows total interest and payoff time.
Vehicle & Loan
Monthly Payment
Loan Totals
How auto loans work
Auto loans use the same amortization math as any fixed-rate installment loan: M = P · r(1+r)n / ((1+r)n − 1). The tricky part is figuring out P, the actual loan amount, because vehicle price alone is not what you finance.
Sales tax + trade-in in most US states
In most states, sales tax applies to the vehicle price minus your trade-in value — a trade-in credit reduces your taxable amount. This calculator uses that model. A handful of states (CA, HI, MI, VA, and a few others as of 2026) tax the full sticker regardless of trade-in; check your state DMV if you need exact figures. Down payment is applied after tax to reduce the loan amount you finance.
Why the APR you get matters more than the sticker
Auto loan APRs vary widely with credit score — the spread between a 720+ FICO and a 620 FICO can be 5+ percentage points, which on a $25k / 60mo loan is thousands in extra interest. Get pre-approved by your credit union or bank before you shop; dealer financing quotes look better when you already have a competing offer.