How to add sales tax to a price
Multiply the price by the tax rate divided by 100 to get the tax. Add that to the price to get the total.
total = price + price × rate ÷ 100
A shortcut is to multiply the price by 1 plus the rate as a decimal. For 8% tax, multiply by 1.08.
Example
An item costs 50 and the tax rate is 8%. The tax is 50 × 0.08 = 4, so the total is 54.
Take the tax out of a total
If a price already includes tax, divide it by 1 plus the rate as a decimal to get the price before tax. A total of 54 with 8% tax gives 54 ÷ 1.08 = 50.
Tips work the same way
Adding a tip is the same calculation. A 15% tip on a bill of 40 is 40 × 0.15 = 6, so the total is 46. Use the quick buttons under the calculator for common rates.
Common questions
Does this work for VAT and GST?
Yes. VAT, GST and sales tax are all a percentage added to a price, so the calculation is the same. Enter the rate that applies to what you are buying.
Which tax rate should I use?
It depends on where you are and what you are buying. Check your local tax authority or the receipt for the exact rate.
How do I remove tax from a price that includes it?
Divide the total by 1 plus the tax rate as a decimal. A total of 108 with 8% tax gives 108 ÷ 1.08 = 100 before tax.