How to use the auto loan calculator
Start with the vehicle's listed price, then enter any negotiated discount, your cash down payment, APR, and loan term. You can add your trade-in value and payoff, manufacturer rebates, sales tax, title and registration fees, and optional dealer add-ons like extended warranties or GAP coverage. The calculator shows the amount financed, your monthly payment, total interest, and the cash you need at signing.
What goes into the amount you finance
- Negotiated price plus any upgrades or accessories.
- Sales tax and fees such as title, registration, documentation, and inspection fees, if you choose to finance them.
- Dealer add-ons like service contracts or GAP coverage, if financed.
- Minus your cash down payment, rebates, and positive trade-in equity (or plus any negative equity).
Example: 60 vs. 72 months
Financing $35,000 at 7% APR for 60 months costs about $693 per month and roughly $6,600 in total interest. Stretching the same loan to 72 months lowers the payment to about $597, but total interest rises to roughly $8,000. The lower payment costs you about $1,400 more overall, and you will be paying for the car for an extra year.
Tips for a better car loan
- Get pre-approved by a bank or credit union before visiting the dealer so you can compare offers.
- Negotiate the price, not the payment. Focusing on the monthly payment makes it easy to hide a longer term or extra add-ons.
- Put money down to reduce interest and avoid owing more than the car is worth.
- Pay extra principal when you can. The calculator shows how an extra monthly payment shortens your loan.
Considering an unsecured loan instead? Compare with our personal loan calculator.
Frequently asked questions
How is a car payment calculated?
Your payment is based on the amount financed (vehicle price plus any taxes, fees, and add-ons you finance, minus your down payment, rebates, and trade-in equity), the APR, and the loan term in months, using the standard amortization formula.
Is it better to take a longer car loan to lower my payment?
A longer term lowers the monthly payment but increases total interest and raises the risk of owing more than the car is worth. Many experts suggest keeping auto loans to 60 months or less when possible.
What is negative equity on a trade-in?
Negative equity happens when you owe more on your current car than it is worth. That difference is usually added to your new loan, which increases the amount financed and your monthly payment.
Do I pay sales tax on the full price if I trade in a car?
In many US states, your trade-in value reduces the taxable price of the new vehicle, but rules vary by state. Use the trade-in tax credit option in the calculator if your state allows it.
Should I buy dealer add-ons like GAP coverage or extended warranties?
They are optional. Financing add-ons means paying interest on them for the life of the loan. Compare prices from your insurer or credit union before agreeing, and decide whether you actually need the coverage.
This guide is for general education and is not financial, tax, or legal advice. See our disclaimer.