GST Calculator
Add 10% GST to a price, or work out the GST in a price that includes it.
$1,000.00 plus GST is $1,100.00. The GST is $100.00.
GST is 10% of the price before GST. To add it, multiply by 1.1. To take it out of a price that already includes it, divide by 11 to get the GST (not 10%), or divide by 1.1 to get the price before GST.
Rates checked September 2026 against the ATO.
How to add GST to a price
GST in Australia is 10% of the price before GST. To add it, multiply the price by 1.1.
Example: a job priced at $2,400 before GST. The GST is $240 and the price including GST is $2,640.
How to work out the GST in a price that includes it
When a price already includes GST, the GST is one-eleventh of it. Divide the price by 11 to get the GST, or divide by 1.1 to get the price before GST.
Example: a receipt for $550 including GST. The GST is $550 / 11 = $50, and the price before GST is $500.
Taking 10% off a GST-inclusive price is a common mistake. On $550 it gives $55, which is $5 too much, because the GST was 10% of $500, not of $550.
Who has to register for GST
You must register for GST when your business's GST turnover is $75,000 or more a year ($150,000 for a non-profit), or when you expect it to reach that. Taxi and ride-share drivers must register from their first dollar, whatever their turnover.
Below the threshold, registering is optional. Registering lets you claim back the GST on business purchases, but you then have to charge GST on your sales and lodge a business activity statement (BAS).
Once registered, the GST you collect isn't yours. Keep it aside and pay it to the ATO with your BAS, less the GST credits on your business purchases. The sole trader tax calculator shows how much of each invoice to hold back for GST and income tax together.
What GST doesn't apply to
Some things are GST-free, so there's no GST to add or remove. The most common are:
- most basic food, such as fresh fruit, vegetables, meat, bread and milk
- many health and medical services, and some medicines
- most education courses
- exports, and some childcare
Frequently asked questions
10%. It has been 10% since GST started on 1 July 2000.
Divide the total by 11. On a $1,100 total the GST is $100, and the price before GST is $1,000.
Multiply by 1.1. A $1,000 price becomes $1,100 including GST.
Because GST is 10% of the price before GST. In a GST-inclusive price, the GST is 10 parts out of 110, which is one-eleventh, or about 9.09%.
Only if you're registered. You must register once your GST turnover reaches $75,000 a year, or from the start if you drive a taxi or ride-share. Below that it's your choice.
No. If you aren't registered you can't charge GST or show it on your invoices, and you can't claim GST credits on what you buy.