Sales Tax Calculator
Find the sales tax amount and total cost of a purchase, or work backward from a tax-inclusive price to find the pre-tax amount.
Back into the pre-tax price from a tax-inclusive total.
Your sales tax results will appear here
Enter the price and tax rate, then click calculate to see the tax amount and total.
Quick Answer
A sales tax calculator finds the tax amount by multiplying your purchase price by the local tax rate, then adds that to the price for your total cost.
How It Works: Formula & Variables
Tax Amount = Price × (Tax Rate ÷ 100) · Total = Price + Tax Amount
- Price
- The pre-tax price of the item or purchase.
- Tax Rate
- Your combined state and local sales tax rate, entered as a single percentage.
Worked Examples
Example 1: Simple state tax
A $250 purchase in a state with 7% sales tax has a tax amount of $250 × 0.07 = $17.50, for a total of $267.50.
Example 2: Combined state and local tax
A $1,200 purchase across a combined state and local tax of 8.875% (such as in NYC) has a tax amount of $1,200 × 0.08875 = $106.50, for a total of $1,306.50.
Key Concepts
Combined rates stack: Your total sales tax rate is usually the sum of state, county, and city tax rates.
Exemptions exist: Items like groceries and prescription drugs are exempt or taxed at reduced rates in many states.
Destination-based tax: Sales tax is destination-based in most U.S. states, meaning the rate is based on where the buyer takes possession of the item.
Common Mistakes
Using only the state rate: Ignoring local county and city add-ons leads to underestimating the true tax owed.
Assuming uniform taxation: Not all items are taxed the same — some are exempt or taxed at reduced rates.
Applying tax before discounts: Tax should be calculated on the discounted price, not the original price, when a discount applies.
Frequently Asked Questions
Multiply the pre-tax price by your combined tax rate to get the tax amount, then add that to the price for your total.
Many states allow counties and cities to add their own local sales tax on top of the state rate, which is why the combined rate can vary significantly within the same state.
It depends on the state — many states exempt groceries entirely or tax them at a reduced rate, while prepared foods and restaurant meals are usually taxed at the full rate.
Turn on 'price already includes tax' and enter the tax-inclusive total — the calculator divides by (1 + tax rate) to find the original pre-tax price.