What is Idaho's car sales tax rate?

Idaho applies its flat 6% state sales tax to motor-vehicle purchases. There is no separate reduced automotive rate. A small number of Idaho resort cities add a local option sales tax, but most vehicle purchases are taxed at the straight 6% state rate.

Does a trade-in reduce the tax in Idaho?

Yes. Idaho taxes the net price after a trade-in when you trade a vehicle to a licensed dealer, so only the difference between the new car's price and the trade-in value is taxable. Enter the trade-in amount to lower the taxable base and the tax owed.

Is private-party purchase taxed in Idaho?

Yes. If you buy a vehicle from a private seller, you pay the 6% use tax to the Idaho DMV when you title and register it, based on the purchase price (or fair market value if the price looks unusually low). The trade-in deduction generally applies only to dealer transactions.

Are dealer doc fees taxed?

Idaho dealer documentation (doc) fees are part of the taxable price of the vehicle, so the 6% sales tax applies to them. Add your doc fee to see the tax it adds; this calculator includes an optional field so you can see the full taxable amount.

Does this include registration and title fees?

No. This tool computes only the 6% sales/use tax on the purchase. Idaho's age-based registration fee and the one-time title fee are additional costs paid at the DMV. Use the Idaho Vehicle Registration Fee Calculator to estimate those separately.

Idaho Car Sales Tax Calculator

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Idaho charges its flat 6% state sales tax on vehicle purchases — there is no separate reduced automotive rate. The tax applies to the price after a qualifying trade-in, plus any taxable dealer doc fee. A few resort cities add a local option tax, but most buyers pay the straight 6%. This tool estimates what you’ll owe at registration.

How it works

The taxable amount is the price plus doc fee minus a dealer trade-in, and the tax is that amount times the combined rate:

taxable    = max(0, purchase price + doc fee − trade-in allowance)
rate %     = 6% (state) + optional resort-city %
sales tax  = taxable × rate %

The trade-in credit is real in Idaho for dealer sales: only the net difference is taxed. Private-party sales are taxed as use tax on the purchase price when you register.

Example and notes

A 30,000 dollar car with a 10,000 dollar dealer trade-in and a 300 dollar doc fee, taxed at the 6% state rate: the taxable base is 30,000 + 300 − 10,000 = 20,300, and the tax is 20,300 × 0.06 = 1,218 dollars. This figure is sales tax only — add the age-based registration fee and the one-time title fee for the full DMV cost. If you buy in a resort city with a local option tax, add that rate; confirm with the Idaho State Tax Commission.