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Sales Tax Reverse Calculator

Extract the original pre-tax price and tax amount from a total that already includes sales tax or VAT.

$

The receipt total including sales tax

%

Your local sales tax or VAT rate

Enter a total amount and tax rate, then click Calculate to extract the pre-tax price.

How Reverse Sales Tax Calculation Works

What is a Reverse Sales Tax Calculation?

A reverse sales tax calculation lets you extract the original pre-tax price and the tax amount from a total that already includes sales tax. This is useful when you have a receipt showing only the final amount and need to know how much went to tax.

When Would You Use This?

You’d use a reverse sales tax calculator when reconciling receipts for expense reports, bookkeeping, or tax filings where you need to separate the tax from the total. It’s also handy for comparing pre-tax prices across states with different tax rates, or for backing out VAT from inclusive pricing used in many countries outside the US.

The Formula

The math is straightforward:

  • Pre-tax Price = Total Amount ÷ (1 + Tax Rate ÷ 100)
  • Tax Amount = Total Amount − Pre-tax Price

For example, if you paid $86.40 and the local tax rate is 8%:

  • Pre-tax Price = $86.40 ÷ 1.08 = $80.00
  • Tax Amount = $86.40 − $80.00 = $6.40

This calculator also supports adding multiple line items so you can process an entire receipt at once and see the combined pre-tax total and total tax paid.

Frequently asked questions

To reverse calculate sales tax, divide the total amount (tax included) by 1 plus the tax rate as a decimal. For example, if the total is $108 and the tax rate is 8%, divide $108 by 1.08 to get the pre-tax price of $100. The tax amount is $108 minus $100, which equals $8.

The formula is: Pre-tax Price = Total Amount ÷ (1 + Tax Rate ÷ 100). Then, Tax Amount = Total Amount − Pre-tax Price. For example, with a $54.25 total and 7% tax: $54.25 ÷ 1.07 = $50.70 pre-tax, and $54.25 − $50.70 = $3.55 in tax.

The average combined state and local sales tax rate in the US is approximately 6.6%. However, rates vary significantly by state and locality. Five states (Alaska, Delaware, Montana, New Hampshire, Oregon) have no state sales tax, while some areas in states like Louisiana, Tennessee, and Arkansas can have combined rates exceeding 10%.

Yes! The reverse calculation formula works the same way for VAT (Value Added Tax). Simply enter the VAT-inclusive total and the VAT rate. For example, with a UK VAT rate of 20%, enter 20 as the tax rate. The formula Pre-tax = Total ÷ 1.20 will give you the net price before VAT.

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