GST Calculator Australia (10%)
Australian GST is 10%. To add GST, multiply the price by 1.1: $1,000 plus GST is $1,100. To find the GST in a GST-inclusive price, divide it by 11: a $1,100 price includes $100 GST and is $1,000 excluding GST. Businesses with GST turnover of $75,000 or more must register for GST.
Choose whether to add GST to a price or take it out of a GST-inclusive amount. The result shows the price excluding GST, the GST and the total, rounded to the cent, ready for a tax invoice or your BAS.
GST formula
GST = price excluding GST × 10%; price including GST = price excluding GST × 1.1. GST in a GST-inclusive price = price ÷ 11; price excluding GST = price ÷ 1.1.
Worked example
| Case | Amount |
|---|---|
| Price excluding GST | $1,000.00 |
| GST 10% | $100.00 |
| Price including GST | $1,100.00 |
| GST in a $49.95 GST-inclusive price | $4.54 |
| $2,200.00 including GST: ex-GST price + GST | $2,000.00 + $200.00 |
Frequently asked questions
How do I calculate GST in Australia?
Multiply the price by 10% to get the GST, or by 1.1 to get the GST-inclusive price. $1,000 plus GST is $1,100, of which $100 is GST.
How do I work out the GST from a total?
Divide the GST-inclusive total by 11 to get the GST, or by 1.1 to get the price excluding GST. A $1,100 invoice includes $100 GST and $1,000 excluding GST.
When do I have to register for GST?
When your GST turnover is $75,000 or more, or $150,000 or more for a non-profit organisation, and within 21 days of knowing you will reach it. Taxi and ride-sourcing drivers must register whatever their turnover. Below the threshold, registration is optional.
What is a GST-free sale?
A GST-free sale carries no GST, but you can still claim GST credits for the purchases you made to provide it. Examples include most basic food, many health and medical services, some education courses and exports.
What must a tax invoice show?
If a customer asks, you must issue a tax invoice for a taxable sale of more than $82.50 including GST. It shows your ABN, the date, what you sold and the GST, and for sales of $1,000 or more the buyer’s identity or ABN.
How is GST rounded?
Round the GST on each invoice to the nearest cent, as this calculator does. $49.95 including GST holds $4.54 of GST ($49.95 ÷ 11 = $4.5409).
Related tools: GST calculator India, profit margin calculator, markup calculator. More on sales and running a sales team on the SalesBond blog and the home page.
Official sources
- Australian Taxation Office: how Australian GST works — 10% rate, GST is 1/11 of the price, $75,000 turnover.
- ATO: registering for GST — $75,000 and $150,000 thresholds, taxi and ride-sourcing drivers.
- business.gov.au: register for GST — 21 days to register, worked example.
Updated on Nov 5, 2026. This calculator is for information only and is not tax, legal or payroll advice. Results follow the formulas above; check your situation with the ATO or a registered tax agent.
