How GST is calculated
GST is a broad-based 10% tax on most goods, services and other items sold or consumed in Australia. To add GST, multiply the GST-exclusive price by 1.1: $100 becomes $110. To find the GST in a GST-inclusive price, divide by 11: $110 includes $10 GST. Enter an amount and the results update as you type.
Choose Custom rate and enter 0 for GST-free sales, or another rate when checking an overseas invoice.
GST-free sales and registration
Some sales are GST-free, including most basic food, though food eaten on the premises is taxable and the ATO's food lists decide individual items. Businesses must register for GST when GST turnover is $75,000 or more, or $150,000 or more for non-profit organisations, and register within 21 days of reaching the threshold.
This calculator does arithmetic only and is not tax advice. Use the ATO's guidance or a registered tax agent for decisions about your business.
Frequently asked questions
How do I work out GST from a GST-inclusive price?
Choose Remove GST. At 10%, the GST inside a GST-inclusive price is one-eleventh of it; the calculator divides by 1.1 for the price before GST.
Which sales are GST-free?
The ATO lists GST-free sales such as most basic food, some education courses and some health services. Choose Custom rate and enter 0 for a GST-free item.
When does a business need to register for GST?
The ATO requires registration when your GST turnover is $75,000 or more, or $150,000 or more for a non-profit organisation.