GST / VAT Calculator — Add or Remove Tax
Add GST/VAT to a net price, remove GST/VAT from a tax-inclusive total, or find the tax amount — at any custom rate, with net, tax, gross and the calculation all shown.
No uploads • No tracking • No registration
Verify your rate: the quick-select buttons above are example percentages only, not a claim about any country's legally correct GST, VAT or sales tax rate. Tax rates vary by jurisdiction, product category and change over time — always confirm the applicable rate for your situation.
How It Works
Choose add or remove
Depending on whether your amount already includes tax.
Enter the amount and rate
Type any custom tax rate that applies to you.
Read net, tax and gross
All three figures are always shown and clearly labeled.
Privacy note: every calculation runs locally in your browser. Nothing you enter is sent to a server.
The formulas
Gross = Net + Tax
Tax = Gross − Net
How to remove GST / VAT from a total
When a price already includes tax and you need the pre-tax figure, you can't just subtract the tax percentage — the percentage was applied to the smaller net amount, not the total. Divide instead:
Tax = Gross − Net
Worked examples
| Goal | Input | Calculation | Result |
|---|---|---|---|
| Add 10% | Net 200 | 200 × 10% = 20 | Tax 20 · Gross 220 |
| Remove 20% | Gross 120 | 120 ÷ 1.20 = 100 | Net 100 · Tax 20 |
| Remove 15% | Gross 575 | 575 ÷ 1.15 = 500 | Net 500 · Tax 75 |
| Find tax in a total | Gross 118, 18% | 118 − 118 ÷ 1.18 | Tax 18 · Net 100 |
Tax-exclusive (net) pricing
The displayed price is before tax; tax is added at checkout. Common for US sales tax and B2B invoicing. Use Add tax mode.
Tax-inclusive (gross) pricing
The displayed price already contains the tax. Common for consumer VAT/GST in the EU, UK, Australia and India. Use Remove tax mode to get the net figure.
Frequently Asked Questions
How do I add GST or VAT to a price?+
Multiply the net (pre-tax) amount by the tax rate to get the tax amount, then add it to the net amount to get the gross (tax-inclusive) total. For example, 100 plus 20% tax is 100 + 20 = 120.
How do I remove GST or VAT from a tax-inclusive price?+
Divide the gross amount by (1 + the tax rate as a decimal) to get the net amount, then subtract the net from the gross to find the tax component. For example, a 120 gross amount at 20% tax has a net amount of 120 ÷ 1.20 = 100, and a tax component of 20. Use the "Remove tax" mode to do this automatically.
How do I calculate VAT backwards from the total?+
Working backwards (reverse VAT) means the price already includes tax and you want the pre-tax figure. Divide the total by (1 + rate/100). At 20%: net = total ÷ 1.2. At 15%: net = total ÷ 1.15. The VAT itself is total − net. The "Remove tax" and "Find tax amount" modes both do this.
What is the difference between tax-inclusive and tax-exclusive pricing?+
A tax-exclusive (net) price is shown before tax and the tax is added at checkout — common in US sales tax and B2B. A tax-inclusive (gross) price already contains the tax — common for consumer VAT/GST in the EU, UK, Australia and India. The same rate produces a different displayed number depending on which convention is used.
What tax rate should I use?+
This calculator does not assume or verify any country's rate. Enter the rate that applies to your specific situation and jurisdiction — tax rates vary by country, region, and sometimes by product or service category, and change over time.
What's the difference between net, tax and gross?+
Net is the amount before tax. Tax is the tax component itself. Gross is the total amount including tax — net plus tax.
Is GST the same calculation as VAT?+
Mathematically, yes — both are percentage-based consumption taxes added to a net price, calculated the same way. The name, exact rules and rate depend on the country's tax system.
Why does removing tax not simply subtract the tax percentage from the gross amount?+
Because the tax rate applies to the net amount, not the gross amount. Subtracting the percentage directly from the gross would overstate the tax removed. Dividing by (1 + rate) correctly reverses the calculation.
Does this tool store the amounts I enter?+
No. All calculations happen locally in your browser. Nothing you enter is sent to a server or saved.