Sales Tax Calculator
In the United States, sales tax is added at the till rather than shown in the shelf price, and the rate depends on where you are: states set a base rate, and counties and cities can add their own. This calculator handles the three jobs people actually have — adding tax to a price to see what you will pay, taking tax out of a total to find the pre-tax price, and working out the rate from a before-and-after pair. Enter your combined rate and it does the arithmetic and shows the steps. For businesses and shoppers outside the US, our VAT and GST calculators do the same with those systems’ conventions.
How to use the sales tax calculator
- Choose whether to add tax, remove tax, or find the rate.
- Enter the amount and your combined state and local sales tax rate.
- Read the total, the tax and the net price, then check the steps.
- To find a rate you do not know, enter the price before tax and the price after tax in “find the rate”.
Formula
Adding tax: tax = price × rate; total = price + tax. Removing tax: net = total ÷ (1 + rate); tax = total − net. Note this is not total × (1 − rate) — taking 8% off a total that already includes 8% tax leaves too little. Finding the rate: rate = (price with tax ÷ price before tax − 1) × 100.
Worked examples
Adding tax
A $100 item at 8.25% sales tax: tax is $8.25 and the total is $108.25.
Removing tax from a receipt total
A receipt shows $108.25 including 8.25% tax. The pre-tax price is $100.00 and the tax paid was $8.25. (Subtracting 8.25% of $108.25 would wrongly give $99.32.)
Finding your local rate
A $50.00 item is charged $54.25 at the till. The implied rate is 8.5%.
How US sales tax works
US sales tax is set by states, counties and cities, so the combined rate differs from one place to the next. Some states, such as Oregon and Montana, charge no statewide sales tax. Many exempt groceries or clothing; services are taxed in some states and not others. Online sellers are generally required to collect tax based on the buyer’s location.
Quick mental maths
- 10% is the price with the decimal moved one place left. For 8%, take 10% and subtract a fifth of it.
- To remove 8% tax from a total, divide by 1.08 (do not subtract 8%).
Outside the US? Try the VAT calculator or GST calculator.
Practice problems
Try these yourself first, then check your answer. The answers come from the calculator above.
- A $64.90 receipt includes 9% sales tax. What was the price before tax?
Show answer
Price before tax (net): $59.54 · Sales tax included: $5.36
Common mistakes to avoid
- Subtracting the tax percentage from the total instead of dividing by (1 + rate).
- Using the state rate only. Local (county or city) rates are added on top in many places.
- Applying tax to exempt items. Groceries, clothing, medicine and other categories are exempt or reduced in some states.
- Forgetting that some jurisdictions tax shipping or delivery.
- Rounding each line item instead of the total — businesses follow their state’s rounding rules, so receipts can differ by a cent.
Frequently asked questions
How do I calculate sales tax?
Multiply the price by the tax rate (as a decimal). For 8% on $50, 50 × 0.08 = $4 tax, for a total of $54.
How do I take sales tax out of a total?
Divide the total by 1 plus the rate. $108 with 8% tax included is 108 ÷ 1.08 = $100 before tax.
What is my sales tax rate?
It is your state rate plus any county or city rate. Your state’s revenue department or a local receipt will show it; the “find the rate” option can work it out from a receipt.
Do all US states charge sales tax?
No. A handful of states, including Oregon, Montana, New Hampshire and Delaware, have no statewide sales tax, though some allow local taxes.
Is sales tax deductible?
In some cases, US taxpayers who itemise can deduct state and local sales taxes instead of income taxes. See the IRS guidance linked below.
Does this work for VAT or GST?
The maths is the same; use the dedicated VAT or GST calculators for presets and notes specific to those taxes.
Sources and further reading
By Thomas M, Registered Investment Adviser (South Carolina), who launched his own financial advisory firm in 2010. Last reviewed September 26, 2026. Found a mistake? Tell us; see our editorial policy.