Work out the real cost of a car loan. In the Total Price tab, enter the auto price to get your monthly payment; in the Monthly Payment tab, enter a target payment to find the price you can afford. Both account for down payment, trade-in, sales tax, and fees.
Examples
$40,000 car, $5,000 down, 60 months at 7%
With 7% sales tax and $300 in fees paid upfront and no trade-in, you finance $35,000. That's a monthly payment of about $693.04, around $6,583 in total interest, and roughly $8,100 due upfront (down payment + tax + fees).
Working backward from a $600 payment
Switch to the Monthly Payment tab: a $600 payment over 60 months at 7%, with the same $5,000 down and $300 fees, corresponds to an auto price of about $35,300.
Formula
First the amount financed is determined, then it is amortized into equal monthly payments. When the user enables a trade-in tax credit:
Sales tax = tax% × (auto price − trade-in value)
Amount financed = auto price − down payment − trade-in + amount owed on trade-in
− cash incentives (+ tax + fees, if rolled into the loan)
Monthly payment = financed × r / (1 − (1 + r)⁻ⁿ) r = APR ÷ 12, n = months
The Monthly Payment tab inverts this: it converts your target payment back to an amount financed, then solves for the auto price.
Rolling taxes and fees into the loan reduces your upfront cash but means you pay interest on them — paying upfront is cheaper overall.
Before relying on the result
Use the vehicle price, taxable amount, trade-in allowance, payoff balance, fees, incentives, and APR from actual documents. Taxable value and trade-in treatment vary, and this tool does not determine registration, title, dealer, documentation, or local tax rules. It also assumes a fixed rate and no late or extra payments.