Australian GST Calculator
Enter any amount. Get the GST-inclusive and GST-exclusive price instantly. Perfect for invoices, quotes, and pricing decisions.
Enter an amount to calculate GST
How GST is calculated in Australia
Australia's GST rate is 10%. The calculation depends on whether your starting price includes GST or not:
- GST-exclusive price: GST = price × 10%
- GST-inclusive price: GST = price ÷ 11
The "divide by 11" formula works because GST-inclusive prices contain the original amount plus 10%. Mathematically: price ÷ 1.1 gives the GST-exclusive amount, and price ÷ 11 gives the GST component.
GST inclusive vs exclusive prices
GST-inclusive prices show the total amount a customer pays, with GST already added. Australian Consumer Law requires most retail prices displayed to consumers to be GST-inclusive.
GST-exclusive prices show the base amount before GST. Business-to-business invoices and quotes often display prices this way, with GST shown as a separate line item.
When do you need to charge GST?
You must register for GST and charge it on taxable sales if your business has a GST turnover of $75,000 or more per year ($150,000 for non-profit organisations). Below this threshold, registration is optional.
Once registered, you charge 10% GST on most goods and services you sell, and you can claim GST credits on your business purchases.
FAQ
Is GST always 10% in Australia?
Yes. The GST rate in Australia has been 10% since its introduction on 1 July 2000. Some items are GST-free (such as basic food, health services, and education), but when GST applies, it is always 10%.
How do I calculate GST on an invoice?
If your invoice shows GST-exclusive prices, multiply each line item by 0.1 to get the GST amount, then add it to the subtotal. If you have a GST-inclusive total, divide by 11 to find the GST component.
What is a GST-inclusive price?
A GST-inclusive price is the total amount including the 10% GST. For example, if an item costs $100 plus GST, the GST-inclusive price is $110.
Do I need to charge GST if I'm not registered?
No. Only GST-registered businesses can charge GST. If you're not registered, you cannot add GST to your prices or claim GST credits on purchases.
How do I calculate the GST-exclusive amount from a total?
Divide the GST-inclusive amount by 1.1. For example, $110 ÷ 1.1 = $100 (the GST-exclusive amount).