Auto Loan Calculator
Calculate your monthly car payment from vehicle price, trade-in, down payment, and sales tax.
Try an example
$526.13
About this calculator
How This Auto Loan Calculator Works
Enter the vehicle price, trade-in value, down payment, sales tax rate, interest rate, and loan term, and the calculator returns your monthly payment, the amount financed, and the total interest over the loan.
Worked Example
A $32,000 vehicle with a $5,000 trade-in, $2,000 down, 7% sales tax, financed at 6.5% APR over 60 months, comes to $526.13/month. Sales tax adds $1,890 (applied to the price minus the trade-in), bringing the amount financed to $26,890 — with $4,678.02 in total interest over the loan.
The Formula
Amount financed = Price + Sales tax − Trade-in − Down payment, where tax is calculated on the price minus the trade-in value (most states tax the net purchase price, not the full sticker price). The monthly payment then uses the standard loan formula: M = P × [r(1 + r)ⁿ] ÷ [(1 + r)ⁿ − 1], with P as the amount financed, r as the monthly interest rate, and n as the number of months.
Why Trade-In Value Matters Twice
A trade-in reduces the amount financed directly, but in most states it also reduces the taxable amount — you're only taxed on the difference between the new vehicle's price and what your trade-in is worth, not the full price. This is one reason trading in a vehicle can be more tax-efficient than selling it privately and using the cash as a down payment instead, even if the private-sale price would be higher.
For a loan not tied to a vehicle purchase, use the general Loan Calculator instead.
Worked example
A $32,000 car with a $5,000 trade-in, $2,000 down, and 7% sales tax leaves $26,890 financed. At 6.5% APR over 60 months, that's about $526/month — roughly $31,562 total, including about $4,672 in interest.
Frequently asked questions
How is sales tax handled here?
Tax is calculated on the vehicle price minus your trade-in value (how most US states tax a trade-in), then added to the amount financed — check your state's exact rule, since a few tax the full price regardless of trade-in.
Does a bigger trade-in always lower my payment?
Yes — trade-in value reduces both the taxable amount and the amount financed, so it lowers your payment twice over compared to the same cash discount.
Should I finance for longer to lower my payment?
A longer term does lower the monthly payment, but you'll pay more total interest and may owe more than the car is worth for longer — shorter terms cost less overall if the payment fits your budget.
Does this include registration or dealer fees?
No — just the vehicle price, trade-in, down payment, sales tax, and financing. Add any registration, title, or dealer fees to your budget separately.