How to Figure the Sales Tax Portion of a Purchase
- 1). Note the purchase price on your receipt if you do not remember the exact purchase price.
- 2). Multiply the purchase price by the sales tax rate set by your state. If the sales tax rate is 7 percent, and your purchase price is $10, then the sales tax rate is $.70.
- 3). Look at the receipt again. The final cost to you based on the example above would be $10.70. The additional $.70 was the amount of sales tax added to the purchase price.