To add tax, multiply the pre-tax price by (1 + rate ÷ 100). The tax is the difference. To go the other way, divide a tax-inclusive total by (1 + rate ÷ 100) to get the pre-tax price. Do not just subtract the percentage from the total: that removes too much.
Example: $100 at 8.25% tax is $108.25. Working backwards, $108.25 ÷ 1.0825 = $100.00.
Multiply the price by the tax rate as a decimal. At 7% tax, a $40 item has $2.80 tax, so you pay $42.80.
Switch the mode above to “Remove tax from a total” and enter the total you paid. The calculator divides by 1 plus the rate.
It depends on your state, county and city, and some items are exempt. Check your local tax authority or a recent receipt: tax paid ÷ pre-tax price gives the rate.
No, everything is calculated in your browser.
See also: Discount Calculator · Tip Calculator · Percentage Calculator