Add 10% GST to a price or work out how much GST is in a GST-inclusive price. $100 plus GST is $110; and $110 including GST contains $10 of GST, which is one-eleventh of the total.
GST Calculator
Add or remove 10% GST
- Price excluding GST
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- GST
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- Price including GST
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The quick rules
- Add GST: multiply the GST-exclusive price by 1.1.
- GST in a GST-inclusive price: divide by 11.
- Price excluding GST: divide the GST-inclusive price by 1.1.
Taking 10% off a GST-inclusive price is a common mistake: 10% of $110 is $11, but the GST is only $10.
Who has to register for GST?
Businesses must register once their GST turnover reaches $75,000 a year ($150,000 for non-profits), and taxi and ride-sourcing drivers must register regardless of turnover. Registered businesses include GST in their prices and claim GST credits on business purchases.
GST-free items
| Usually GST-free | Usually taxable |
|---|---|
| Basic food (bread, milk, fruit, vegetables) | Restaurant meals, takeaway, snacks |
| Most medical and health services | Cosmetics and most other goods |
| Education courses | Most services |
FAQs
How do I show GST on a tax invoice?
If a customer asks, a GST-registered business must give a tax invoice within 28 days for any taxable sale over $82.50 including GST. The invoice shows the seller's ABN and either the GST amount or a statement that the total price includes GST, along with other details.
Is GST the same in every state?
Yes. GST is a federal tax of 10% across Australia.
Related calculators
Sources
Figures current as of 12 October 2026
Each formula is checked against a separate test sheet with at least three worked examples. Results are estimates based on the numbers you enter and the published rules; your actual figures may differ. This is general information, not financial or tax advice.
Spotted a mistake? Contact us and we will fix it and update the date above.