US Sales Tax Calculator

1. Choose your mode - pick Add tax to a price when you have a pre-tax amount, or Remove tax from a total when you have a final price that already includes tax.
2. Enter the amount - in add mode this is the price before tax, in remove mode it is the tax-inclusive total from your receipt.
3. Enter your combined rate - add up the state rate plus any county, city and special district rates that apply at the point of sale, and type the single combined percentage.
4. Read your results - the calculator updates instantly to show the pre-tax amount, the sales tax, the total including tax, and the effective rate.

Everything recalculates as you type, so there is no submit button. Change the rate or switch modes and the numbers update right away, which makes it quick to compare two locations or check a receipt against the price on the shelf.

The math behind sales tax is simple arithmetic, and knowing it helps you sanity-check any receipt. The calculator first turns your percentage into a decimal rate by dividing by 100. A rate of 8.25% becomes 0.0825.

In add mode, your amount is the pre-tax price. The tax is the price multiplied by the rate, and the total is the price plus the tax. For a $200 purchase at a combined 9.5% rate, the tax is 200 times 0.095, which is $19.00, and the total comes to $219.00.

In remove mode, your amount is a tax-inclusive total and the calculator runs the steps in reverse. Because the total equals the net price times one plus the rate, the pre-tax amount is the total divided by one plus the rate. The tax is then the total minus that net amount. For a $219.00 total at 9.5%, the net is 219 divided by 1.095, which is $200.00, and the tax is $19.00. A common mistake is to multiply the total by the rate directly, which overstates the tax, so dividing is the correct reverse step.

The effective rate the calculator reports is the tax divided by the pre-tax amount, expressed as a percentage. In add mode it equals the rate you entered. In remove mode it confirms that the back-calculation lines up with the rate, which is a useful consistency check.

The large headline figure is the answer to the mode you chose: the total including tax when you are adding tax, or the recovered pre-tax amount when you are removing it. Below it, the breakdown always separates the pre-tax amount, the sales tax and the total, so you can see each component no matter which mode you are in.

Remember that the combined rate you enter drives everything. The United States has no national sales tax, so the rate at one address can differ from the rate a few miles away. Statewide base rates for the 2026 tax year are illustrative only: California 7.25%, Texas 6.25%, New York 4% and Florida 6% are the state portions, and local rates push the real combined figure higher in most places. Look up the exact combined rate for your delivery or purchase address before relying on the result.

Many states also exempt categories such as groceries or prescription medicine, or run temporary sales tax holidays, so the right rate for one item may not apply to another. This calculator is a tool for working out the arithmetic of a single combined rate. It is not tax advice, and for filing or compliance questions you should check your state revenue department or a qualified professional.