Buying & Finance · Free tool
Free Car Sales Tax Calculator
Enter the price, your trade-in and your state and local rates to see the taxable amount, the sales tax and how much the trade-in saves you.
- Free to use
- No signup
- Runs in your browser
The purchase
Your tax rate
Your state revenue department publishes both rates.
Your state’s rules
Estimated sales tax
$1,500
On a taxable amount of $25,000.
- Taxable amount
- $25,000
- State tax (6.00%)
- $1,500.00
- Local tax (0.00%)
- $0.00
- Tax saved by the trade-in
- $0
- Price plus sales tax
- $26,500
- Vehicle and doc fee$25,000
- Sales tax$1,500
Vehicle tax rules differ from state to state. Confirm yours with your state motor vehicle or revenue agency.
An estimate from the figures you enter, not a quote. Read the disclaimer. Updated .
02Your result
What your car sales tax result means
Sales tax is usually the largest fee on a car purchase, and the taxable amount matters as much as the rate.
- 01
Taxable amount
The figure the rate is applied to. In most states that is the price less your trade-in, so it can be far below the sticker.
- 02
Sales tax
State tax plus any county and city tax. It is due when you buy or register the car and is often rolled into the loan.
- 03
Tax saved by the trade-in
What the trade-in credit is worth in tax. It is one reason a trade-in can beat a slightly higher private sale price.
What to do next
Add the other fees
Put tax together with the doc fee, title and registration to see the full out-the-door price.
Out-the-door calculatorSee the payment with tax
Enter your tax rate in the payment calculator to finance the tax with the car.
Car payment calculatorPlan the paperwork
Title transfer, sales tax and registration, in the order they happen.
Paperwork guide
03How it works
The car sales tax formula
The arithmetic is simple. What changes from state to state is what counts as taxable and which rate applies.
Tax = (price + taxable fees − trade-in credit − rebate credit) × (state rate + local rate)
Leave out the trade-in or rebate term if your state taxes the price before it.
What each term means
- P
- The agreed vehicle price.
- F
- Dealer fees that your state taxes, such as a documentation fee.
- T
- Your trade-in value, where the state deducts it before tax.
- R
- A manufacturer rebate, where the state deducts it before tax.
- s, l
- The state rate and the combined county and city rate, as decimals.
What the tool assumes
- One combined percentage rate applies to the whole taxable amount.
- The trade-in and rebate are treated the way you set the three switches.
- Title, registration and plate fees are separate and are not taxed here.
- Flat vehicle taxes, tax caps and luxury surcharges are not modeled.
04Worked example
Car sales tax example with an $8,000 trade-in
A $25,000 car, an $8,000 trade-in, a 6% state rate and a 1% local rate, in a state that taxes the difference.
- 01
Find the taxable amount
$25,000 price − $8,000 trade-in
$17,000
- 02
Add the rates together
6% state + 1% local
7%
- 03
Apply the rate
$17,000 × 7%
$1,190
- 04
Compare with no trade-in credit
$25,000 × 7%
$1,750
- 05
See what the trade-in saved
$1,750 − $1,190
$560
Sales tax due
$1,190
The trade-in credit is worth $560 in tax, on top of the $8,000 itself.
Try your own numbers05Background
How sales tax on a car works
Most states charge sales tax when a car changes hands, and many counties and cities add their own rate on top. Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon.
The rate is only half of the sum. Most states charge tax only on the difference between the car you buy and the one you trade in, which is why the calculator deducts the trade-in by default. A minority tax the full price, so check before you rely on the saving.
Dealer documentation fees are a second variable. In some states the doc fee is limited by law and in others it is unregulated, and states differ on whether it is taxed. The switches under the rate fields let you match your own state.
For where the tax fits in the buying process, see the paperwork section of the used car guide.
06When to use it
When to use a car sales tax calculator
Tax is easy to forget when you are focused on the price. Work it out before you agree a number.
Before you set a budget
Know how much of your money goes to tax, not to the car.
To value a trade-in
Add the tax saving to the dealer’s offer before comparing it with a private sale.
When buying across a border
Compare the tax you would owe at two different combined rates.
To check a buyer’s order
Confirm that the tax line on the dealer’s paperwork matches your own sum.
Mistakes to avoid.
- Using the state rate alone and leaving out county and city tax.
- Assuming your state deducts the trade-in before tax without checking.
- Forgetting that a taxed doc fee adds to the bill.
- Treating title and registration fees as part of sales tax. They are separate charges.
07Related guides and tools
Keep going from here.
Guides that go with this tool
Related tools
08Questions
Car Sales Tax Calculator: your questions.
How do I calculate sales tax on a car?
Multiply the taxable amount by your combined state and local rate. In most states the taxable amount is the price minus your trade-in. For a $25,000 car with an $8,000 trade-in at 7%, the tax is $17,000 × 0.07, or $1,190.
Does a trade-in reduce sales tax?
In most states, yes. The tax is charged on the difference between the price of the car you buy and the value of the one you trade in. A few states tax the full price, so confirm the rule where you register the car.
Which states have no sales tax on cars?
Five states have no statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon. Some of them charge other vehicle fees or allow local taxes, so a purchase there is not always free of tax.
Are dealer fees taxed?
It depends on the state. Documentation fees are taxed in some states and not in others, and some states cap the fee itself. Use the switch in the calculator to match your state.
Is sales tax included in a car loan?
It can be. Tax is due at purchase or registration, and lenders commonly let you finance it with the car, which means you pay interest on it too.
09Estimates and sources
Read this before you rely on it.
Built and checked by CarTipsMentor Team. Last updated . How we check our work.
Sources
- [1]Tax Foundation, State and Local Sales Tax Rates, 2026
- [2]NerdWallet, Does a Trade-In Reduce Sales Tax?
- [3]Edmunds, What Dealer Fees Should You Pay for a New Car? (July 2026)