Auto Loan Calculator
Monthly car payment after down payment, trade-in, and sales tax.
Every calculation runs locally in your browser. Nothing you enter here is sent to a server or stored anywhere. Sales tax rules vary by state — check your local rate before relying on this for a real purchase.
Monthly payment
$459
Loan amount
$23,750
Total interest
$3,799
Total paid over the loan
$27,549
For informational and educational purposes only — not financial, investment, or tax advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why trade-in value affects more than the sticker price
In most U.S. states, sales tax is charged only on the difference between the vehicle price and your trade-in value, not the full purchase price — trading in a $5,000 car against a $30,000 purchase means tax applies to $25,000, not $30,000. That's on top of directly lowering the amount you finance, so a trade-in reduces both your loan principal and the tax you owe.
Frequently asked questions
How does a trade-in affect the loan amount?
The trade-in's value is subtracted from the vehicle price before financing, the same way a down payment is — reducing both the amount you borrow and the total interest you'll pay.
Is sales tax charged on the full price or the price after trade-in?
This varies by state — many US states tax only the price after the trade-in credit, some tax the full price. Check your state's rule and adjust the taxable amount you enter accordingly.
Does this include fees like title, registration, or dealer fees?
No — it covers principal, down payment, trade-in, and sales tax on the vehicle price. Title, registration, and dealer fees vary too much by state and dealer to estimate generically; add them to your down payment for a closer total.