CALCSLIP

Sales tax calculator

Add tax to a price, take it out of a total, or find the rate from two prices.

I know
$
%

State + county + city combined

Result

Price with tax
$270.63
Before tax
$250.00
Sales tax (8.25%)
$20.63
After tax
$270.63

How this was calculated

  1. Tax

    Price × rate ÷ 100

    $250.00 × 8.25 ÷ 100 = $20.63

  2. Price with tax

    Price + tax

    $250.00 + $20.63 = $270.63

What this calculation assumes

  • Taking tax out of a price divides by (1 + rate). Subtracting the rate from the total, a common shortcut, removes too much.
  • US sales tax is set by the state, county and city together; use the combined rate for your address. VAT and GST work the same way for these sums.

Adding tax and taking it out are not mirror images

To add tax you multiply: a $250 item at 8.25% costs $250 × 1.0825 = $270.63. To take tax out of a total you divide by the same factor: $270.63 ÷ 1.0825 = $250.00.

The common shortcut of subtracting 8.25% from the total gives $248.30, which is wrong by $1.70, because 8.25% of the total is more than 8.25% of the price before tax. The bigger the rate, the bigger the error: at 20% VAT the shortcut is off by 4% of the price.

The formulas

Gross = Net × (1 + r) Net = Gross ÷ (1 + r) r = Gross ÷ Net − 1

r is the rate as a decimal (8.25% = 0.0825). The third form finds the rate when you know both prices, for example from a receipt that shows the total but not the tax.

Which rate to use

In the US there is no national sales tax. Each state sets a rate, and counties and cities can add their own, so the rate at the register is the sum of all three. Five states (Alaska, Delaware, Montana, New Hampshire and Oregon) have no statewide sales tax, though some Alaska towns charge one.

Value-added tax (VAT) in Europe and goods and services tax (GST) in Australia, Canada, India and elsewhere are usually already included in shelf prices; use Price with tax to see the tax inside a price.

Questions people ask

How do I calculate tax backwards from a total?

Divide the total by 1 plus the rate. For a $54.00 total with 8% tax: 54 ÷ 1.08 = $50.00 before tax, so the tax was $4.00.

Is sales tax charged on the price before or after a discount?

In most US states, on the discounted price you actually pay. Manufacturer coupons can be different: some states tax the price before the coupon. The discount calculator applies tax after the discount.

Why does my receipt differ by a cent?

Stores round tax per line or per receipt, and some round half-cents up. The difference is rounding, not a different rate.