How GST works in Australia
The Goods and Services Tax (GST) is a broad-based tax of 10% on most goods, services and other items sold or consumed in Australia. It has been set at 10% since it was introduced on 1 July 2000 and has not changed since. Businesses registered for GST add it to their prices, collect it from customers, and pass it on to the Australian Taxation Office, usually through a Business Activity Statement (BAS).
Adding GST to a price
To add GST to a GST-exclusive amount, multiply by 1.1 — or, the same thing, work out 10% and add it on. A $200 service becomes $200 × 1.1 = $220, of which $20 is GST.
Finding the GST inside a price
This is the part people most often get wrong. If a price already includes GST, the GST portion is not 10% of that price — it's the price divided by 11. A $220 GST-inclusive total contains $220 ÷ 11 = $20 of GST, leaving $200 as the GST-exclusive amount. Dividing by 11 works because the total represents 110% of the original price, and 10 ÷ 110 simplifies to 1 ÷ 11.
| You have | To find | Do this |
|---|---|---|
| Price excluding GST | Total including GST | Multiply by 1.1 |
| Price excluding GST | GST amount | Multiply by 0.1 |
| Price including GST | GST amount | Divide by 11 |
| Price including GST | Price excluding GST | Divide by 1.1 |
GST-free and input-taxed items
Not everything carries GST. GST-free items include most basic food, many health and medical services, education courses, child care and exports. Input-taxed items, such as residential rent and most financial services, don't have GST added to their sale price either, but the supplier generally can't claim GST credits on related purchases. This calculator assumes the standard 10% applies.
Registering for GST
A business must register for GST once its annual turnover reaches $75,000 ($150,000 for non-profit organisations). Once registered, it charges GST on taxable sales and can claim credits for the GST in its own business purchases.