Sales Tax Calculator
Calculate sales tax on pre-tax prices or reverse-calculate the subtotal from a tax-inclusive total.
Enter the purchase price before tax and your local sales tax rate.
How Sales Tax Calculations Work
In the United States, sales tax is calculated as a percentage of the taxable purchase price. Forward sales tax multiplies the pre-tax subtotal by the combined state and local tax rate. Reverse sales tax divides the total receipt amount by 1 plus the tax rate to recover the pre-tax price, with the remaining difference representing the exact tax paid.
Mathematical Formula
Forward: Total = Subtotal × (1 + Rate / 100) | Reverse: Subtotal = Total ÷ (1 + Rate / 100)Example 1: Adding 8.25% Sales Tax
Scenario: An item costs $100.00 before tax in an area with an 8.25% combined sales tax rate.
Math: Tax = $100.00 × 0.0825 = $8.25. Total = $100.00 + $8.25 = $108.25.
Result: Total after tax: $108.25 (Tax: $8.25)
Example 2: Reverse Tax from $108.25 Receipt
Scenario: You paid $108.25 total on a receipt with 8.25% sales tax and want to find the pre-tax price.
Math: Subtotal = $108.25 ÷ 1.0825 = $100.00. Tax = $108.25 − $100.00 = $8.25.
Result: Pre-tax subtotal: $100.00 (Tax paid: $8.25)