How to Use the GST Calculator Australia
- Choose whether you want to add GST or remove GST.
- Enter the amount.
- Select Calculate to see the GST amount and the price with and without GST.
How GST Works in Australia
The goods and services tax (GST) is a 10% tax on most goods and services sold in Australia. Businesses registered for GST add it to their prices and pass it on to the Australian Taxation Office. Prices shown to consumers usually already include GST.
How to Add GST
To add GST to a price that doesn't include it, multiply the price by 1.1. The GST itself is the price multiplied by 0.1.
- Price excluding GST: $200.00
- GST: $200 × 0.1 = $20.00
- Total including GST: $200 × 1.1 = $220.00
How to Remove GST
To find the GST inside a price that already includes it, divide the price by 11. To find the price without GST, divide by 1.1.
- Price including GST: $110.00
- GST: $110 ÷ 11 = $10.00
- Price excluding GST: $110 ÷ 1.1 = $100.00
A common mistake is to take 10% off the total. On $110, that gives $11, which is wrong: GST is 10% of the price before GST, so the correct amount is $10.00.
Who Charges GST?
Businesses must register for GST once their annual turnover reaches $75,000 ($150,000 for non-profits). Registered businesses charge GST on their sales and can usually claim back the GST they pay on business purchases as GST credits. Some items are GST-free, including most basic food, many medical services and most education courses. Source: ATO — GST.
GST-free is different from "input-taxed", a smaller category that includes things like residential rent and most financial services. Sales in both categories have no GST added, but a business making input-taxed sales generally can't claim back the GST on related purchases — while one making GST-free sales usually can. The distinction rarely matters for everyday shopping, but it matters a lot for how a business calculates its own BAS.
GST on Invoices and Receipts
If you're registered for GST, your invoices should show whether prices include GST and how much GST was charged. To claim a GST credit on a business purchase over $82.50 (including GST), you need a tax invoice from the supplier. For smaller purchases, a receipt showing the GST is usually enough. Keep these records for five years.
BAS and GST Reporting
If you're registered for GST, you report and pay it to the ATO through a Business Activity Statement (BAS), usually lodged quarterly, though some businesses report monthly or annually depending on turnover. Each BAS nets off the GST you collected on sales against the GST credits you're claiming back on business purchases — you only pay (or get refunded) the difference. Keeping clean tax invoices for every purchase over $82.50 makes this reconciliation straightforward; missing invoices are the most common reason a GST credit gets disallowed at tax time. Source: ATO — business activity statements (BAS).
GST and Your Income
If you're a sole trader, the GST you collect isn't your income — it belongs to the ATO. Sole trader? Also check your Income Tax Calculator Australia to estimate the tax on your earnings. Employee instead? Use our Take Home Pay Calculator Australia to see your net pay after tax.