US Car Loan Calculator with Trade-In and Sales Tax
Estimate a US car loan in dollars: monthly payment, total interest, your state sales tax, trade-in equity including any amount still owed, and 36 to 84-month terms compared.
US auto loan: out-the-door price, trade-in and loan terms
This simulator models a financed car purchase in the United States, in dollars: price + sales tax + dealer fees give the out-the-door price, from which the down payment and net trade-in (trade-in value minus the payoff still owed) are deducted. It then compares payments and interest over 36, 48, 60, 72 and 84 months. With the default values, $29,020 financed at 6.5% costs $568 a month over 60 months.
How it works
Net trade-in = trade-in value − payoff owed on the old vehicle. Sales tax = (price − trade-in value) × rate. Amount financed = price + tax + fees − down payment − net trade-in. The payment follows M = P × r × (1 + r)^n / ((1 + r)^n − 1), with r = APR / 12. Displayed amounts are rounded to the dollar.
Worked example
A $35,000 car, $5,000 down, $4,000 trade-in with nothing owed, 7% sales tax, $850 in fees, 6.5% APR. Tax: 7% of $31,000 = $2,170; out-the-door price: $38,020; financed: $29,020. By term:
| Term | Payment | Interest |
|---|---|---|
| 36 months | $889 | $3,000 |
| 48 months | $688 | $4,014 |
| 60 months | $568 | $5,049 |
| 72 months | $488 | $6,103 |
| 84 months | $431 | $7,178 |
If you still owe $6,000 on the trade-in ($2,000 of negative equity), that balance is rolled into the loan: $35,020 financed, $685 a month and $6,092 of interest over 60 months.
Assumptions and limits
- Deducting the trade-in before tax applies in many US states, not all: check your state's rule and adjust the rate if needed.
- No insurance, extended warranty or manufacturer rebate.
- No month-by-month amortization table is shown.
Unlike the site's general car loan calculator, which works in any currency and ignores trade-in payoffs, this tool targets US purchases and term comparison. An indicative estimate that does not replace your lender's offer.
Frequently Asked Questions
What is a car's out-the-door price?
It is what you actually pay to drive off the lot: vehicle price + sales tax + documentation and registration fees. With the default values ($35,000, 7% tax on $31,000, $850 in fees) it comes to $38,020. The amount financed is then that figure minus the down payment and the net trade-in.
What happens if I owe more on my car than its trade-in value?
The difference, called negative equity, is rolled into the new loan. With a $4,000 trade-in and $6,000 still owed, the amount financed rises from $29,020 to $35,020; the 60-month payment goes from $568 to $685 and interest from $5,049 to $6,092.
How much more does an 84-month car loan cost than a 36-month one?
For $29,020 at 6.5%, the payment is $889 over 36 months and $431 over 84 months. Interest climbs from $3,000 to $7,178, more than double. The tool's table shows all five terms side by side.
Is sales tax charged after deducting the trade-in?
The tool taxes the price minus the gross trade-in value, even if a payoff is still owed on it. Many US states grant this trade-in credit, but not all. If yours does not, the actual tax will be higher than the estimate.
Is this tool really free?
Yes, all tools on Kristools are 100% free and accessible without registration.
Is my data protected?
Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.