GST Calculator

To add GST: multiply the GST-exclusive amount by 1.1. For example, $100 × 1.1 = $110 inclusive of GST. To remove GST: divide the GST-inclusive amount by 11, which gives you the GST component. Or divide by 1.1 to get the GST-exclusive amount. For example, $110 ÷ 1.1 = $100 exclusive of GST, and the GST component is $10.

You must register for GST if your business has a GST turnover of $75,000 or more per year ($150,000 for non-profit organisations). You can choose to register voluntarily if your turnover is below this threshold. Taxi drivers and ride-sharing drivers must register regardless of turnover.

Some common GST-free items include: most basic foods (bread, milk, fruit, vegetables, meat), some medical and health services, some educational courses, exports, and certain childcare services. Items that are "input taxed" (like residential rent and financial supplies) don't include GST either, but the rules differ from GST-free supplies.

If you're registered for GST, you must issue tax invoices that show the GST amount for sales over $82.50 (including GST). For sales of $82.50 or less, you can issue a regular invoice. Your invoice should clearly state whether prices are GST-inclusive or GST-exclusive, and show the total GST amount.