Amount Financed
$32,100.00
Auto Loan Calculator
Calculate monthly payment and total cost for a vehicle loan.
Monthly Payment
$628.07
Sales Tax
$2,100.00
Total Interest
$5,584.40
Total Cost
$42,684.40
What is the Auto Loan Calculator?
An auto loan calculator estimates the monthly payment and total cost of financing a vehicle. Unlike a plain loan calculator it accounts for the down payment, a trade-in, and sales tax on the purchase — the pieces that decide how much you actually finance.
The formula
Find the amount financed, then apply the standard loan payment formula:
Amount financed = Price + Sales tax − Down payment − Trade-in
M = A · r(1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)- A
- amount financed
- r
- monthly rate = annual rate ÷ 12
- n
- number of monthly payments (the term in months)
In most U.S. states sales tax is charged on the price after the trade-in credit, which lowers the tax.
Worked example
A $35,000 car with $5,000 down, no trade-in, 6% sales tax, financed at 6.5% over 60 months.
Tax is $2,100, so the amount financed is $32,100. The monthly payment is $628.07, total interest is $5,584.40, and the all-in cost is $42,684.40.
Prefer your own numbers? Enter them in the calculator above — it recomputes instantly.
Key terms
- Amount financed
- The loan balance after down payment, trade-in and tax are applied.
- Trade-in
- The value your old vehicle knocks off the price (and often the taxable amount).
- Negative equity
- Owing more on the loan than the car is worth — common early in long terms.
- Term
- Loan length in months; longer terms lower the payment but raise total interest.
Frequently asked questions
Does a longer term lower the payment?
Yes, but it raises total interest and keeps you underwater — owing more than the car is worth — for longer.
Should I put more down?
A larger down payment lowers both the payment and total interest, and reduces the risk of negative equity.
Is sales tax charged on the trade-in?
In most U.S. states tax applies to the price minus the trade-in value, which lowers it — but rules vary by state.