Car loan calculator: what it estimates
This free car loan calculator estimates the amount you may need to finance, your scheduled monthly principal-and-interest payment, total interest, total loan payments and an estimated payoff date. It also lets you model a down payment, trade-in, sales tax, fees, financed add-ons and extra monthly payments.
How to use the auto loan calculator
- Enter the vehicle price and your planned down payment.
- Add a trade-in value and, if applicable, the payoff amount on the existing trade-in loan.
- Enter the sales-tax rate, fees and any optional products you plan to finance.
- Enter the interest rate or APR and loan term.
- Review the monthly payment, total interest and total loan payments.
- Try an extra monthly payment to see how the modeled payoff time and interest change.
How a car payment is calculated
For a standard amortizing auto loan, the monthly payment is based on the amount financed, the monthly interest rate and the number of monthly payments. When the rate is zero, the amount financed is divided evenly across the term. With a positive rate, the calculator uses the standard fixed-payment amortization formula.
What goes into the amount financed?
The estimate starts with the vehicle price and adds modeled sales tax, fees and financed add-ons, then subtracts the down payment and trade-in value. If you still owe money on the trade-in, the tool can either leave that payoff outside the new loan or model the negative equity as rolled into the new loan. The tax calculation can optionally apply a trade-in tax credit. Because state and local tax treatment differs, use the controls to match your situation as closely as possible.
APR vs. interest rate
APR is a broader measure of borrowing cost and can include certain fees. Your loan documents may show both an interest rate and an APR. For the payment calculation, this tool treats the entered percentage as the periodic rate used to amortize the loan, so it is best used with the rate provided for the payment calculation and then checked against the lender's disclosure.
Why the monthly payment is not the whole story
A longer loan term can reduce the required monthly payment while increasing the total interest paid. The FTC recommends comparing the total cost of financing rather than focusing only on the monthly payment. The CFPB likewise recommends comparing the amount financed, APR, loan length and monthly payment when evaluating auto loan offers.
Down payments and trade-ins
A larger down payment generally reduces the amount you need to borrow. A trade-in can also reduce the amount financed, but if you still owe money on the trade-in, that payoff matters. The calculator therefore asks for both trade-in value and any existing payoff so you can model the net equity more clearly.
Extra payments: how much can you save?
If your contract allows extra principal payments without a prepayment penalty, paying more than the scheduled amount can shorten the modeled payoff period and reduce interest. The calculator compares the standard schedule with your selected extra monthly payment and reports estimated interest and months saved.
Frequently asked questions
What is a car loan calculator?
It is a tool that estimates auto-loan payments and costs from inputs such as vehicle price, amount financed, interest rate, term, taxes and fees.
How much will my monthly car payment be?
It depends on the amount financed, rate and term. A larger down payment lowers the amount financed; a higher rate or shorter term generally increases the required monthly payment.
Does a trade-in reduce my car loan?
Usually, the value credited for the trade-in can reduce the amount you need to finance. If the old vehicle still has a loan balance, that payoff can reduce the trade-in's net equity.
Does sales tax work the same in every state?
No. Tax treatment, including how trade-ins affect taxable price, can vary by state and locality. This calculator provides an estimate and includes a trade-in tax-credit option for that reason.
Is APR the same as the interest rate?
Not necessarily. APR is a broader measure of the cost of credit and may include certain fees. Check your lender's disclosure for the exact rate, APR and finance charge.
Can I pay off a car loan early?
Some auto loans can be prepaid without a penalty, but contract terms vary. Check your loan agreement before relying on an early-payoff assumption.
Methodology and sources
The calculator's categories and educational guidance are informed by consumer-finance material from the Consumer Financial Protection Bureau (CFPB) and Federal Trade Commission (FTC). These sources emphasize considering amount financed, APR, term, taxes, fees, trade-ins and total cost rather than focusing only on the monthly payment.