How to use this auto loan calculator
Enter the vehicle price you've negotiated, then subtract what you're bringing to the table: your cash down payment and the trade-in value of your current car. Add your state's sales tax rate and any title, registration, or dealer fees you plan to roll into the loan, then the interest rate (APR) and term from your financing offer. The calculator shows the amount you'll actually finance — which is often noticeably higher than the sticker price once tax and fees are added — along with your monthly payment, total interest, and the true all-in cost of the vehicle.
What the amount financed includes
The loan amount is calculated as: price − down payment − trade-in + sales tax + fees. By default, sales tax is applied to the price minus your trade-in, which is how most U.S. states calculate it — one of the underrated financial benefits of trading in rather than selling privately. A few states (California, for example) tax the full price regardless of trade-in, so check your state's rule and adjust the tax field if needed.
Tips for a smarter car loan
- Keep the term short. 72- and 84-month loans lower the payment but sharply raise total interest, and they keep you "upside down" (owing more than the car is worth) for years. Aim for 60 months or less.
- Put 10–20% down. Cars depreciate fastest in the first two years. A real down payment keeps your loan balance below the car's value, protecting you if it's totaled or you need to sell.
- Get pre-approved before visiting the dealer. A credit-union or bank pre-approval gives you a rate to beat and turns the dealership finance office into a comparison shop instead of a negotiation.
- Negotiate the price, not the payment. Dealers can make almost any car "fit your monthly budget" by stretching the term. Settle the vehicle price first, then apply your own financing numbers here.
- Test extra payments. Even $50 extra per month meaningfully shortens a car loan — use the extra payment field and the chart to see your payoff date move.
Frequently asked questions
- How is a car payment calculated?
- The amount financed (price − down payment − trade-in + tax + fees) is amortized with the standard loan formula over your term at your APR — the same math as the general loan calculator, with the car-specific inputs handled for you.
- Is sales tax charged on the full price or after trade-in?
- Most states tax the price minus your trade-in value, which this calculator does by default. A few states tax the full price. Either way the tax is commonly rolled into the loan, which means you pay interest on it.
- What's a good auto loan term?
- 36–60 months is the sweet spot: lower rates, less interest, and less time underwater. Longer terms only make sense when the rate is heavily subsidized and you'd invest the difference.
- New or used — does the calculator care?
- The math is identical; only the numbers differ. Used-car APRs run higher than new-car promotional rates, while new cars depreciate faster. Run both scenarios and compare the total cost line, not the monthly payment.