Reverse Sales Tax Calculator — Remove Tax from Total

Enter the total amount including tax and the tax rate to calculate the pre-tax price and the tax amount. Perfect for expense reports, budgeting, and accounting. 100% free, no sign-up.

Total Amount (with tax)

Tax Rate (%)

What do you want to do next?

Sales Tax Calculator Calculate sales tax for all 50 US states. VAT Calculator Add or remove VAT for UK/EU rates.

Free Reverse Sales Tax Calculator Online

OptiDrop's Reverse Sales Tax Calculator helps you find the original price before tax was added. When you have a receipt total that includes sales tax, this tool instantly calculates how much of that total is the actual item price and how much is tax. All calculations happen in your browser — nothing is uploaded.

How Does Reverse Sales Tax Work?

The reverse sales tax formula divides the total amount by (1 + tax rate / 100). For example, if you paid $108 total and the tax rate was 8%, the pre-tax price is $108 / 1.08 = $100.00, and the tax was $8.00. This is the standard method used by accountants and bookkeepers to back-calculate pre-tax amounts.

When to Use This Calculator

This tool is useful for expense reports where you need to separate tax from totals, business accounting and bookkeeping, budgeting to understand true product costs, and tax filing where you need to itemize tax paid. It works with any percentage-based sales tax rate worldwide.

Frequently Asked Questions

To find the pre-tax price, divide the total amount (including tax) by (1 + tax rate/100). For example, if the total is $108 and the tax rate is 8%, the pre-tax price is $108 / 1.08 = $100. The tax amount is then $108 - $100 = $8.

The formula is: Pre-tax Price = Total Price / (1 + Tax Rate / 100). The tax amount = Total Price - Pre-tax Price. This calculator applies this formula automatically so you don't have to do the math manually.

You need a reverse sales tax calculator when you have a receipt total that includes tax and want to know the original item price. This is useful for expense reports, business accounting, budgeting, or when you need to separate the tax amount from the total for tax filing purposes.

Yes. This calculator works with any sales tax rate from 0% to 100% or higher. Simply enter the tax rate that was applied to your purchase. It works for US state sales taxes, Canadian GST/HST, or any other percentage-based tax.

Last updated: June 2026