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Auto Loan Calculator with Trade In and Sales Tax

An auto loan calculator works out your monthly car payment from the vehicle price, down payment, trade in value, sales tax, interest rate, and term. This free tool shows the amount you actually finance, the total interest, and the full payment schedule. Everything runs in your browser, with no signup.

Updated for 2026

Your car loan

Drag a slider or type a value. Results update instantly.
$
$
$
%
% APR
Estimated monthly payment
$0
Amount financed
$0
Sales tax
$0
Total interest
$0
Total cost
$0

Amortization schedule

The schedule shows how each payment splits between interest and principal over the life of the loan. Switch between a yearly summary and the full monthly view.

YearPrincipalInterestBalance

How a car payment is calculated

First work out the amount financed, then apply the standard amortizing loan formula:

Loan = Price + Sales tax − Down payment − Trade in
M = Loan × [ r(1 + r)n ] / [ (1 + r)n − 1 ]

where r is the APR divided by 12 and n is the term in months. Sales tax is charged on the price minus the trade in, which most US states allow.

Worked example (Stand: 2026)
  • Vehicle price$35,000
  • Down payment$5,000
  • Trade in$3,000
  • Sales tax (6 percent on $32,000)$1,920
  • Amount financed$28,920
  • Monthly payment (60 months, 6.5 percent)$566
  • Total interest$5,031

Frequently asked questions

How is a car payment calculated?
Find the amount financed by adding sales tax to the price and subtracting the down payment and trade in. Then apply M = Loan times r times (1 + r)^n divided by ((1 + r)^n minus 1), where r is the APR divided by 12 and n is the term in months.
Does a trade in reduce sales tax?
In most US states, yes. Tax is charged on the price minus the trade in, which lowers both the tax and the amount financed. A few states tax the full price, so check your state. This tool taxes the price minus the trade in.
Should I make a bigger down payment?
A larger down payment lowers the amount financed, so it cuts the monthly payment and total interest, and reduces the chance of owing more than the car is worth. Raise the down payment above to see the effect.
Is a longer term cheaper?
A longer term lowers the monthly payment but raises the total interest, and you stay in debt on the car longer. Compare 60 and 72 months with the term control to see the trade off.
Does this calculator store my information?
No. Every calculation runs in your browser. Nothing you type is sent to a server or saved.

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