Sales tax is the price × the rate, added to the price: $100 at 7% is $7.00 of tax and $107.00 in all. To go back, divide the total by 1 plus the rate. You enter the rate, because it is set by each state and place.
The formula
Tax and total from a price
tax = price × rate ÷ 100 · total = price + taxPrice before tax from a total
pre-tax price = total ÷ (1 + rate ÷ 100) · tax = total − pre-tax priceMoney is rounded to the cent, with half a cent rounding up. The United States has no national sales tax: rates are set by states, counties and cities, and they change. See the Tax Foundation's state and local sales tax rates for a comparison, and use the rate for the place you are buying in.
Worked example
Now go backwards from that $54.11: 54.11 ÷ 1.0825 = 49.986…, which is $49.99 before tax, and 54.11 − 49.99 leaves $4.12 of tax.
When to use it, and the mistakes to avoid
Use it to check a receipt, to budget for a purchase before you reach the till, or to work out what an item cost before tax when you only know what you paid.
- Taking the rate off the total. To remove 7% tax from $107, divide by 1.07. Subtracting 7% of $107 is wrong.
- Using only the state rate. Counties and cities add their own, so use the combined rate.
- Typing 0.07 for 7%. The rate is a percentage, so enter 7.
- Taxing exempt items. Groceries and medicine are often exempt or taxed less.
- Expecting the receipt to match to the cent. Stores round at different steps.
FAQ
How do I calculate sales tax?
Multiply the price by the tax rate as a decimal, then add the result to the price. On a $100 item at 7%, the tax is 100 × 0.07 = $7.00 and the total is $107.00. Enter the price and your rate, and the calculator shows both.
How do I find the price before tax from a total?
Divide the total by 1 plus the rate as a decimal. If you paid $107.00 with 7% sales tax, the price before tax was 107 ÷ 1.07 = $100.00. Do not take 7% off the total: 7% of $107 is $7.49, which is more than the tax actually in it.
What is the sales tax rate in my state?
It depends on the state, county and city, so there is no single answer and this page does not guess one. Look up the combined rate for where you are buying on your state's department of revenue site, or read it from a receipt: tax paid ÷ price before tax. Five states have no state sales tax at all (Alaska, Delaware, Montana, New Hampshire and Oregon), though Alaska allows local taxes.
Why does my receipt differ by a cent?
Because of rounding. This calculator rounds the tax on the whole price to the nearest cent, with half a cent rounding up. A store may round each item's tax and then add them up, or round at a different step, so a receipt with several items can differ from one calculation on the total by a cent or two.
Is everything subject to sales tax?
No. Many states exempt groceries, prescription medicine or clothing, or tax them at a lower rate, and some tax services as well as goods. The calculator applies the one rate you give it to the whole amount, so use the rate that applies to the item.