How to Back out Sales Tax, Working Percentages

By eHow Contributor

If you are shopping and come across an item that states "sales tax included", do you ever wonder how much of the price goes towards the sales tax, and how much is the actual price of the item? If you know the sales tax rate (percentage) you can easily "back out the tax" by a simple calculation on your pocket calculator.

Determine the sales tax rate for the item you are purchasing. Is the sales tax 6%, 15%?

Enter the total amount due on your calculator. Assume the total is $13.65. Enter that amount.

Hit the divide key on your calculator, it may be / or ÷.

Enter the calculation that will determine the price without the percentage. What is that calculation? If the percentage is 5%, the number you enter will be 1.05. If it is 6% you will enter 1.06. If the percentage is 8% the number you enter will be 1.08. If your percentage is 25% you will enter 1.25. If your percentage is 14% you will enter 1.14. As you can see, you will be entering number one, followed by the percentage number of the sales tax.

Hit the equal key, and the answer will reflect the total without the tax.