Add or remove GST and see the net, tax and gross amounts.
Calculated locally in your browser.
Understanding your result
Use “Add” when your price excludes tax, and “Remove” when the price already includes GST and you need the tax component.
Formula and method
Add: GST = Amount × Rate ÷ 100; Gross = Amount + GST. Remove: Net = Amount ÷ (1 + Rate ÷ 100); GST = Amount − Net.
Worked example
Adding 18% GST to 1,000 gives 180 tax and a 1,180 total. Removing 18% from 1,180 returns the 1,000 net.
How to use this tool
- Enter the amount.
- Set the GST rate.
- Choose Add GST or Remove GST.
- Press Calculate.
Common mistakes to avoid
- Using “Add” on a price that already includes GST.
About the GST Calculator
Add Goods and Services Tax to a net price, or extract the GST already included in a gross price.
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Frequently asked questions
What GST rate should I use?
Rates vary by country and product. Enter the rate that applies in your jurisdiction.