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Reverse Sales Tax Calculator

The pre-tax price inside a total that already includes sales tax, and the tax it contains. Useful for expense claims and for splitting a receipt that shows only the final figure.

Also called: reverse sales tax, sales tax backwards, extract sales tax.

$
%
That amount is
%
$
Total with sales tax
$108.25

$100.00 plus $8.25 of sales tax at 8.25% comes to $108.25. Only one rate applied. Most US receipts combine a state rate with a county and often a city rate. Nothing exempt. Groceries, medicine and sometimes clothing are zero rated in many states.

Before tax
$100.00
Tax
$8.25
Combined rate
8.25%
At the base rate
$8.25
At the local rate
$0.00
Taxable portion
$100.00
Total for the quantity
$108.25
Tax per unit
$8.25
On the rate split
Only one rate applied. Most US receipts combine a state rate with a county and often a city rate.
On exempt items
Nothing exempt. Groceries, medicine and sometimes clothing are zero rated in many states.
How this is calculated

Computed from the published rates for the tax year you selected, which is not necessarily the current year. A calculation, not tax advice, and it does not know anything about your circumstances beyond the figures entered.

Method and background

This is what the calculation gives for the numbers you entered. It is an estimate, not advice, and it knows nothing about your situation beyond those numbers. Rules for United States change on a published schedule; the effective date is shown on every rule-based tool.

How this is calculated

Divide the total by one plus the combined rate. Subtracting the rate from the total is the intuitive move and is wrong: it takes the percentage of the larger number, so it removes more than was ever added.

the rates stack additively, and only the non-exempt portion is taxed
A
Amount
E
Exempt portion

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

108.25 inclusive at 8.25%

Amount
$108.25
Sales tax rate
8.25%
That amount is
Amount already includes tax

Total with sales tax$108.25

Exact division

Open this example

a 7% total

Amount
$107.00
Sales tax rate
7%
That amount is
Amount already includes tax

Total with sales tax$107.00

arithmetic identity

Open this example

no tax to extract at a zero rate

Amount
$100.00
Sales tax rate
0%
That amount is
Amount already includes tax

Total with sales tax$100.00

degenerate case

Open this example

Method and limits

What it assumes

  • Rates stack additively, which is how US sales tax works and not how a VAT chain does.

What it deliberately does not model

  • Rates vary by exact address rather than by city, and some jurisdictions have district taxes on top.
  • What is exempt differs by state, particularly for groceries, clothing and prepared food.
  • Origin and destination sourcing rules decide which jurisdiction applies for remote sales.

Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator

Frequently asked questions

How do I get the tax out of a total that already includes it?
Divide by one plus the rate, not multiply by the rate. Taking 8.25 percent of a tax-inclusive total overstates the tax, because that total is already 108.25 percent of the net.
Why does the rate differ across town?
Because city and district taxes stack on the state rate, and the boundaries follow addresses rather than postcodes. Two shops a street apart can charge different rates legitimately.