How to Calculate Pretax
- 1). Find the sales tax of where you are purchasing the item. For example, assume the sales tax is 4 percent. In decimal form, this is 0.04.
- 2). Find the total amount you paid for the good on your receipt. In the example, assume you spent $10.54.
- 3). Divide the total price by one plus the tax rate. In the example, $10.54 divided by 1.04 equals a pretax price of $10.14.