Calculating Sales Tax: Formula, Before-Tax and After-Tax Price
Learn how to calculate sales tax, total purchase price, and pre-tax price from a tax-inclusive total.
Searching calculating sales tax means you want to know how much tax is added to a purchase.
Sales Tax Formula
Sales tax = Price x Tax rate
If the rate is a percentage, convert it to a decimal first.
Example
If an item costs $80 and sales tax is 7.5%:
Sales tax = 80 x 0.075 = $6
Total price = 80 + 6 = $86
Reverse Formula: Find the Pre-Tax Price
If you know the total and need the pre-tax price:
Pre-tax price = Total / (1 + Tax rate)
The Bottom Line
To calculate sales tax, multiply the price by the tax rate, then add the result to the original price. Use the Tax Calculator for quick tax math.
How to Calculate: Step-by-Step Guide
Find the tax rate
Use the local sales tax rate as a percentage.
Multiply by the price
Convert the tax rate to a decimal and multiply by the pre-tax amount.
Add tax to the subtotal
Combine the tax amount with the original price to get the total.