Work out the price before tax and the tax amount from a tax-inclusive price.
Calculated instantly in your browser.
How do you calculate the price before tax from a tax-inclusive price?
Net = gross ÷ (1 + rate ÷ 100), and Tax = gross − net. This removes tax rather than adding it, which is useful for invoicing and bookkeeping when you know the total paid and need to separate the tax portion. For example, a 120 price including 20% tax breaks down to 100 net plus 20 tax.
Understanding your result
Useful for invoicing and bookkeeping when you know the total paid and need to separate the tax portion.
Formula and method
Net = gross ÷ (1 + rate ÷ 100). Tax = gross − net. This removes tax rather than adding it.
Assumptions and limitations
Figures are estimates for general guidance only and not financial or tax advice. Accuracy depends on entering the correct tax rate, which the tool cannot verify, and rates and exemptions vary by country and item. Your reporting obligations depend on your registration and local rules, so confirm the treatment with a qualified professional where it matters.
Worked example
A 120 price including 20% tax breaks down to 100 net plus 20 tax.
How to use this tool
- Enter the tax-inclusive (gross) price.
- Enter the tax rate.
- Press Calculate.
About the Reverse Tax (VAT/GST) Calculator
The Reverse Tax Calculator extracts the tax already included in a price, showing the net (pre-tax) amount and how much of the price is VAT or GST.
Who should use this tool
Sole traders, bookkeepers and finance teams who know a tax-inclusive total and need to separate the pre-tax net amount from the VAT or GST inside it. Useful for invoicing, expense claims and reconciling receipts where only the gross price is shown but the tax portion must be recorded.
Benefits
- Splits a gross price into net and tax
- Works from the total when only the gross is known
- Supports bookkeeping and accurate expense claims
- Keeps your figures private in the browser
Practical use cases
- Separating tax from a receipt total for accounts
- Recording the net amount on an expense claim
- Checking the tax portion of a supplier invoice
- Reconciling a paid total during bookkeeping
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Frequently asked questions
Why isn’t the tax just 20% of the total?
Because the 20% was added to the net price, not the gross. On a 120 gross at 20%, the tax is 20 (which is 20% of the 100 net), not 24.
Why isn't the tax simply the rate applied to the total?
Because the tax was originally added to the smaller net amount, not the gross total. Applying the rate to the whole price overstates it. The tool divides the gross by one plus the rate to recover the net first, so a 120 total at 20% yields 100 net and 20 tax, not 24.
Can I use this when the price already excludes tax?
No. This tool assumes the price you enter already includes the tax and works backwards to remove it. If your price excludes tax and you want to add it, use a standard VAT or GST calculator in add mode instead, which multiplies the net by the rate.