Auto Loan Calculator
This auto loan calculator estimates your monthly car payment from the vehicle price, down payment, trade-in, sales tax and fees, and shows the amount financed, total interest and total cost of the loan.
Result
$573.29 per month
| Sales tax | $1,800.00 |
|---|---|
| Amount financed | $29,300.00 |
| Total interest | $5,097.29 |
| Total cost (down payment + loan) | $37,397.29 |
Results update as you type.
How the Auto Loan Calculator Works
A car loan finances whatever isn’t covered up front. The calculator builds the amount financed step by step, then applies the standard monthly payment formula.
1. Sales tax
- If your state lets a trade-in reduce the taxable price: tax = (price − trade-in value) × tax rate
- Otherwise: tax = price × tax rate
2. Amount financed
Amount financed = price + sales tax + fees + owed on trade-in − down payment − trade-in value
3. Monthly payment
Payment = P × r ÷ (1 − (1 + r)^−n), where P is the amount financed, r = APR ÷ 12 and n = months.
4. Totals
- Total interest = payment × n − amount financed
- Total cost = down payment + amount financed + total interest
Worked Example
A $35,000 car with $3,000 down, a $5,000 trade-in (nothing owed), 6% sales tax, $500 in fees, at 6.5% for 60 months, in a state where the trade-in reduces taxable price:
- Taxable price: $35,000 − $5,000 = $30,000
- Sales tax: $30,000 × 6% = $1,800
- Amount financed: $35,000 + $1,800 + $500 − $3,000 − $5,000 = $29,300
- Monthly payment: $573.29
- Total interest: $5,097.29
- Total cost (down payment + loan): $37,397.29
If the state taxes the full price instead, the tax is $2,100 and $300 more is financed.
Tips for Using the Calculator
Negotiate the price, not the payment
A low monthly payment can hide a long term or a higher price. The total interest and total cost lines show the full picture.
Watch for negative equity
If you owe more on your current car than it’s worth, rolling the difference into the new loan increases both the payment and the interest. The CFPB also suggests confirming with your old lender that the previous loan was actually paid off after a trade-in.
Compare terms
Try 48, 60 and 72 months. Longer terms cut the payment but raise the interest, and the balance stays higher for longer.
Related calculators
To work out sales tax on its own, use the sales tax calculator. For other fixed-rate loans, try the loan calculator.
Frequently Asked Questions
How is a car payment calculated?
First the calculator works out the amount financed — price plus sales tax and fees, minus the down payment and trade-in, plus anything still owed on the trade-in. Then it applies the standard loan formula, payment = P × r ÷ (1 − (1 + r)^−n). On the default example, $29,300 financed at 6.5% for 60 months is about $573.29 a month.
Does a trade-in reduce sales tax?
It depends on your state. Some states tax only the price minus the trade-in value; others tax the full price. The calculator has a setting for this, and your state's department of revenue or the dealer can confirm which applies.
What happens if I owe more on my trade-in than it's worth?
That difference is negative equity. The CFPB notes that a dealer or lender may offer to roll it into the new loan, but that makes the new loan more expensive. Enter the amount owed on the trade-in and the calculator adds it to the amount financed.
Is a longer car loan a good idea?
A longer term lowers the monthly payment but increases total interest, as the CFPB explains for auto loans. The calculator shows total interest so you can compare 48, 60 and 72-month terms side by side.
What fees should I include?
Common ones include title, registration and documentation fees. They vary by state and dealer. Add them in the fees box if they'll be financed; leave them out if you're paying them up front.
Why is my dealer's payment different?
Dealers may include add-ons such as service contracts or GAP coverage, use a different rate, or apply taxes differently. Ask for an itemized breakdown and compare it with the calculator.
Related Calculators
- Loan CalculatorMonthly payment, total interest and amortization for any fixed-rate loan.
- Sales Tax CalculatorAdd sales tax to a price, or remove it from a total.
- Mortgage CalculatorFull monthly mortgage payment, including taxes, insurance and PMI.
- Debt Payoff CalculatorSnowball vs avalanche plan for paying off several debts.
Sources
- Consumer Financial Protection Bureau — What is amortization and how could it affect my auto loan? (longer terms mean lower payments but more interest)
- Consumer Financial Protection Bureau — Should I trade in my car if it's not paid off? (rolling a remaining balance into a new loan makes it more expensive)
- Whether a trade-in reduces the taxable price varies by state; the default rate, fees and APR are example inputs, not typical values.
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