What is a car loan calculator?
A car loan calculator turns a sticker price into the number that actually matters when you're shopping: your monthly payment. It accounts for your down payment, trade-in, sales tax, interest rate, and loan length, then shows what you'll pay each month and how much of the total is interest versus the car itself. Running a few scenarios before you walk into a dealership is the single best way to avoid being talked into a longer term or a payment you can't comfortably carry.
How to use this calculator
- Enter the vehicle price, then your down payment and any trade-in value — both reduce how much you borrow.
- Add your sales tax rate and APR. The tax applies to the price minus your trade-in in most states; the APR depends on your credit.
- Choose a loan term and press Calculate to see the monthly payment, amount financed, total interest, and total cost.
Example
You're buying a $35,000 car with $5,000 down and a $3,000 trade-in, in a state with 8% sales tax, financed at 6% APR over 60 months. Tax is charged on $32,000 (price minus trade-in), adding $2,560. You finance $29,560, giving a monthly payment of about $572. Over five years you'll pay roughly $4,728 in interest. Stretch the same loan to 72 months and the payment drops near $490 — but total interest climbs above $5,700.
Frequently asked questions
How is a car loan payment calculated?
Your payment spreads the amount financed over the term using amortization: M = P × r / (1 − (1 + r)−n), where P is the amount financed, r is the monthly rate (APR ÷ 12), and n is the number of months.
Does a trade-in reduce sales tax?
In most US states, yes — the trade-in value is subtracted from the price before tax, lowering both what you finance and the tax owed. A few states tax the full price regardless.
What is included in the amount financed?
Vehicle price plus sales tax, minus your down payment and trade-in. Title and registration fees can also be rolled in; this calculator focuses on price, tax, down, and trade-in.
How does the loan term affect my payment?
A longer term lowers the monthly payment but raises total interest, since you borrow longer. A shorter term costs more monthly but saves overall. Compare a few terms to find your balance.
What APR should I expect?
It depends on your credit score, new vs. used, and the lender. Strong credit gets the lowest rates; used cars and weaker credit carry higher ones. Get pre-approved to know your real number before shopping.