GST Calculator Australia

How GST Works in Australia

The Goods and Services Tax (GST) is a 10% tax applied to most goods, services, and other items sold or consumed in Australia. Introduced on 1 July 2000, it is collected by businesses registered for GST and remitted to the Australian Taxation Office (ATO). Not all items attract GST — basic food, some medical services, and certain educational courses are GST-free.

If you run a business with a turnover of $75,000 or more ($150,000 for non-profit organisations), you are required to register for GST, charge it on your sales, and lodge Business Activity Statements (BAS) to report and pay the GST you have collected.

Using the GST Calculator

Our GST calculator makes it easy to add or remove GST from any amount. Enter a dollar value and choose whether you want to add GST (calculate the GST-inclusive price) or remove GST (find the GST-exclusive price from a total that already includes tax). The calculator instantly shows the GST component and the final amount.

This is useful for invoicing, quoting jobs, reconciling receipts, and preparing BAS lodgements. Freelancers, sole traders, and small business owners use GST calculators daily to ensure their pricing and bookkeeping are accurate.

Common GST Mistakes to Avoid

One frequent error is calculating GST by simply taking 10% of the GST-inclusive amount. To find the GST in an inclusive price, you must divide by 11 — not multiply by 10%. For example, the GST on a $110 inclusive item is $10 (110 ÷ 11), not $11. Our calculator handles this automatically, so you never have to worry about getting the maths wrong.

Another common mistake is failing to claim GST credits on business purchases. If you are registered for GST, you can claim back the GST included in the price of goods and services you buy for your business. Keeping accurate records and receipts ensures you do not miss out on credits that reduce your overall tax liability.