Sales Tax Calculator
Add sales tax to a price, or work backwards to strip the tax out of a tax-inclusive total.
Tax: $4.00 on a $50.00 price.
An 8% sales tax on a $50 price is 50 × 8 ÷ 100 = $4, for a $54 total. Working backwards, a $54 tax-inclusive total at 8% means a pre-tax price of 54 ÷ 1.08 = $50. Change the amount or rate and both directions update.
How sales tax works
Sales tax is a percentage added on top of a price at the point of sale. Multiply the price by the rate to get the tax, then add it back to reach the total you actually pay. In the United States the rate is usually shown exclusive of tax — the shelf price is pre-tax and the tax appears at the register — so the total is always a little higher than the sticker.
total = price + tax · reverse: pre-tax = total ÷ (1 + rate ÷ 100)
Worked example
A $50 item with an 8% sales tax.
- 1 Multiply the price by the rate. 50 × 8 = 400.
- 2 Divide by 100 to get the tax. 400 ÷ 100 = $4.
- 3 Add the tax to the price. $50 + $4 = $54 total.
- 4 To reverse it, divide the total by 1 + rate. $54 ÷ 1.08 = $50 pre-tax.
Common rates on a $50 price
Sample rates only — actual sales tax, GST, and VAT rates vary by country, state, county, and city, and some goods are taxed at reduced or zero rates.
| Rate | Tax on $50 | Total |
|---|---|---|
| 5% | $2.50 | $52.50 |
| 8% | $4.00 | $54.00 |
| 10% | $5.00 | $55.00 |
| 15% | $7.50 | $57.50 |
| 20% (VAT) | $10.00 | $60.00 |
Sales tax vs. VAT, and tax-inclusive pricing
U.S. sales tax is charged once, at the final retail sale, and is added on top of the listed price. VAT (value-added tax, common in Europe) and GST (goods and services tax) are collected in stages along the supply chain, and the price on the shelf is usually tax-inclusive — the total you see already contains the tax.
That difference is exactly why the reverse calculation matters. When a price already includes tax, you cannot just multiply by the rate to find the tax; you have to divide the total by 1 + rate ÷ 100 to recover the pre-tax amount, then subtract. A $54 total at 8% is $50 pre-tax plus $4 tax — not $54 × 0.08. Use the reverse mode whenever you are handed a tax-inclusive figure and need the net price, for example to log an expense or reclaim VAT.