Sales Tax Calculator: Add, Remove or Find the Rate
To add sales tax, multiply the price by the tax rate and add the result: $50 at 8.25% is $50 × 0.0825 = $4.13 in tax, for a total of $54.13.
Total with tax
$54.13
Sales tax
$4.13
Rates vary by state, county and city. Your receipt or local tax authority has the exact combined rate.
Show the math
- 1
Work out the tax
$50.00 × 8.25 ÷ 100 = $4.13
8.25% is 0.0825 as a decimal.
= $4.13
Read the steps as text
- Work out the tax. $50.00 × 8.25 ÷ 100 = $4.13 8.25% is 0.0825 as a decimal.
- Add it to the price. $50.00 + $4.13 = $54.13
Adding and removing sales tax
Adding tax is a simple percentage: convert the rate to a decimal, multiply it by the price, and add that to the price. You can also multiply by 1 plus the rate in one step, so $50 × 1.0825 = $54.13.
Removing tax from a total is where people often go wrong. The tax was calculated on the pre-tax price, not on the total, so you can't just take 8.25% off the total. Instead divide the total by 1 plus the rate: $108.25 ÷ 1.0825 = $100.00. Taking 8.25% off $108.25 would wrongly give $99.32.
Finding the rate from a receipt
If you know the price before tax and the total you paid, subtract to get the tax, then divide by the pre-tax price and multiply by 100. A $100 purchase that came to $107 was taxed at $7 ÷ $100 × 100 = 7%.
US sales tax is set by states, counties and cities, so the combined rate depends on exactly where you buy. Five states (Alaska, Delaware, Montana, New Hampshire and Oregon) have no statewide sales tax, though some Alaska towns add their own.
Frequently asked questions
- How do I calculate sales tax?
- Multiply the price by the tax rate as a decimal. For a 7% rate on $40, that's $40 × 0.07 = $2.80 in tax, so you pay $42.80.
- How do I find the price before tax?
- Divide the total by 1 plus the tax rate. If you paid $54.13 including 8.25% tax, the pre-tax price was $54.13 ÷ 1.0825 = $50.00.
- Why can't I just subtract the tax percentage from the total?
- Because the tax was a percentage of the smaller, pre-tax price. Taking the same percentage of the larger total removes too much.
- How is the tax rounded?
- Usually to the nearest cent, with half a cent rounded up, which is what this calculator shows. A few states use slightly different rounding rules or bracket tables.