Car Loan Calculator
The short answer: enter the price, what you're putting down, your trade-in, the APR, and the term — this calculator returns the monthly payment, the total interest, and the all-in cost of the car, using the same amortization formula lenders use. Change any number and the result updates instantly, so you can feel what a point of APR or a year of term actually costs.
Get pre-approved before you shop
A pre-approval turns this estimate into a real rate you can hold every seller to — and it costs nothing to check. LendingTree's auto loan marketplace (application via CJ) is the planned partner for this slot.
How this is calculated
The amount financed is the price, minus your down payment and trade-in, plus sales tax on the taxable amount (price minus trade-in, the rule in many states). The monthly payment then comes from the standard amortization formula M = P × r(1+r)n ÷ ((1+r)n − 1), where P is the amount financed, r is the APR divided by 12, and n is the term in months. Total interest is the sum of all payments minus the amount financed. Sanity check you can verify anywhere: $20,000 at 9% APR for 60 months is a $415.17 payment and about $4,910 of interest — this calculator returns the same figures.
What it leaves out, honestly: dealer fees, title and registration, and any add-ons rolled into a real loan. Add those to the price if you want them counted. For the thinking behind the math, read our guide to car loans & total cost.
Frequently asked questions
How is a car loan payment calculated?
With the standard amortization formula: M = P × r(1+r)n ÷ ((1+r)n − 1), where P is the amount financed, r is the monthly rate (APR ÷ 12), and n is the number of monthly payments. Early payments are mostly interest; later payments are mostly principal.
Does a trade-in reduce the sales tax?
In many states, yes — tax is charged on the price minus the trade-in value. Rules differ by state, and a few states tax the full price. This calculator applies tax to price minus trade-in; check your state's rule for the exact figure.
What APR should I use?
The APR from an actual pre-approval or lender quote for your credit profile and the car's age. Used-car APRs commonly run higher than new-car APRs, and older cars often carry higher rates. If you're guessing, run the calculator at two or three rates to see the range.
Why does the term change the total so much?
A longer term lowers the monthly payment but keeps the balance higher for longer, so more interest accrues. On a $20,000 loan at 9%, stretching from 48 to 72 months drops the payment by roughly $138 a month but adds about $2,000 in interest.