Sales tax on a car is calculated as a percentage of the purchase price, and the rate depends on your state and sometimes your county or city

The amount you pay in sales tax when buying a car is the vehicle's selling price multiplied by your state's tax rate. That rate ranges from zero in states like Montana, Oregon, and New Hampshire to over 7% in states like Tennessee and Arkansas. Some states also allow counties or cities to add their own tax on top of the state rate, which can push your total to 10% or higher in certain areas.

The tax is usually collected by the dealer at the time of sale and sent to your state's revenue department. You'll see it listed separately on your bill of sale or purchase agreement, so you know exactly what portion of your payment goes to tax versus the actual vehicle cost.

Key Takeaways

  • Sales tax on cars is calculated by multiplying the purchase price by your state's tax rate, which varies from 0% to over 7% depending on where you live.
  • Some states allow counties or cities to add local sales tax on top of the state rate, potentially raising your total tax to 10% or more.
  • The dealer collects the tax at the point of sale and remits it to the state, so the amount owed is determined before you leave the lot.
  • Trade-in value, rebates, and financing do not reduce the taxable amount in most states — tax is calculated on the full selling price.
  • A few states tax only the difference between the new car price and your trade-in value, which can save you hundreds of dollars.

What your state's tax rate actually is

Every state sets its own sales tax rate, and that rate applies to car purchases. States with no sales tax at all include Montana, Oregon, New Hampshire, Delaware, and Alaska. States with the highest rates include Tennessee (9.55%), Arkansas (6.5% state plus local), and Washington (6.5% state plus local). Most states fall between 5% and 7%.

To find your state's rate, search "[your state] sales tax rate" or check your state's department of revenue website. The rate is usually listed clearly, and many sites also show whether local taxes apply in your area. If you live near a state border, you may be tempted to buy across the line to avoid tax — but most states tax based on where the car is registered, not where it was purchased, so you'll owe tax regardless.

How local taxes can increase what you owe

In addition to state sales tax, many counties and cities impose their own sales tax on vehicles. These local rates typically range from 0.5% to 2.5%, though some areas go higher. If your state rate is 6% and your county adds 1.5%, your total tax rate is 7.5%.

Local tax rates change by location, so two buyers in the same state can owe different amounts depending on their county or city. When you buy a car, the dealer knows your registration address and applies the correct combined rate. If you're buying in one location but registering in another, ask the dealer which rate will apply — this matters most if you're buying out of state or moving soon after purchase.

Trade-ins and rebates: what actually gets taxed

In most states, you pay sales tax on the full selling price of the car, even if you're trading in an old vehicle or receiving a rebate. A $30,000 car with a $5,000 trade-in means you owe tax on $30,000, not $25,000. The trade-in value is subtracted from what you owe the dealer, but the tax calculation happens first.

A small number of states — including New York, Vermont, and a few others — use what's called a "trade-in credit" system. In those states, you pay tax only on the difference between the new car price and the trade-in value. That means a $30,000 car with a $5,000 trade-in would be taxed as a $25,000 purchase. If you live in one of these states, this can save you hundreds of dollars. Check your state's rules before assuming you'll pay tax on the full price.

Financing, down payments, and the total you owe

The amount you finance or the size of your down payment does not change the sales tax you owe. Tax is based on the purchase price alone. If you buy a $25,000 car, you owe tax on $25,000 whether you pay cash, put down $10,000 and finance $15,000, or finance the entire amount. The tax is due at the time of sale, regardless of how you're paying for the vehicle.

Some buyers assume that if they finance through the dealer, the tax gets rolled into the loan. It does not — the tax is a separate line item on your paperwork, and you pay it upfront (or it's added to your loan balance if you choose to finance it). Either way, the amount owed is the same.

Used cars and private sales

Sales tax on used cars is calculated the same way as new cars — as a percentage of the purchase price. The age of the vehicle does not matter. If you buy a used car from a dealer, the dealer collects and remits the tax just as they would for a new car.

If you buy a used car from a private seller, the tax rules depend on your state. Some states require you to pay sales tax when you register the vehicle, based on the purchase price you report. Others do not tax private sales at all. A few states tax private sales but at a lower rate than dealer sales. Check your state's department of motor vehicles or revenue department to learn the rule where you live, because the responsibility to pay may fall on you rather than the seller.

How to estimate your total cost before you buy

To calculate what you'll owe in sales tax, multiply the purchase price by your combined state and local tax rate. If you're buying a $28,000 car in a state with a 6% rate and a county with a 1% rate, your tax is $28,000 × 0.07 = $1,960. Add that to the purchase price to see your true out-of-pocket cost before any financing.

When you're shopping, use this calculation to compare the real cost of buying in different locations or at different times. Some dealers offer sales tax holidays or promotions, though these are rare for vehicles. More commonly, the tax rate is fixed by law, so the only way to reduce what you owe is to negotiate the purchase price itself.

Frequently Asked Questions

Do I pay sales tax on a car I buy out of state?

You pay sales tax based on where you register the vehicle, not where you buy it. If you register it in your home state, you owe your state's tax rate. Some states require you to pay tax when you register, even if you bought the car in a state with no sales tax. Check your state's rules before buying out of state.

Can I deduct sales tax on a car from my income taxes?

No, sales tax on a vehicle purchase is not deductible on your federal income tax return. You can deduct state and local taxes (SALT) if you itemize deductions, but only up to $10,000 per year total, and this includes all state and local taxes combined, not just car sales tax.

What if the dealer and I disagree on the sales tax amount?

The tax rate is set by law and is not negotiable. If you think the amount is wrong, check your state's tax rate and your county's rate, then verify the dealer applied the correct combined rate to the purchase price. If there's still a discrepancy, contact your state's department of revenue — they can confirm what you should have paid.

Do I owe sales tax if I buy a car from a family member?

Most states tax sales between family members the same way they tax any private sale. Some states exempt gifts or sales between close relatives, but this varies widely. Check your state's department of motor vehicles to learn whether a family sale is taxed and at what rate.