GST Calculator
Australia's Goods and Services Tax (GST) is a broad-based tax of 10% applied to most goods, services, and other items sold or consumed in Australia, introduced on 1 July 2000 under the A New Tax System (Goods and Services Tax) Act 1999. The 10% rate is applied to the net (ex-GST) price: GST amount = net price × 10%; and to extract GST from a GST-inclusive price: GST amount = total ÷ 11 (because inclusive = net + GST). Key GST-free supplies include most fresh food, medical services, childcare, and education. Small businesses with annual turnover below ,000 are not required to register for GST (though they may choose to). GST-registered businesses lodge Business Activity Statements (BAS) monthly or quarterly and remit net GST to the ATO. This calculator handles both directions: adding GST to a net price, and extracting GST from a GST-inclusive total.
How Australian GST Works
Australia's Goods and Services Tax is a 10% levy applied to most goods and services sold or consumed in Australia. Introduced in 2000, it is collected by businesses on behalf of the ATO and passed on to consumers as part of the purchase price. Most items you buy include 10% GST, the price you see is the price you pay.
Registered businesses with an ABN and GST turnover of $75,000 or more must be registered for GST. They can claim credits for the GST included in their business purchases (input tax credits). This calculator works in both directions: add GST when calculating what to charge customers, and remove GST when working out the GST component of a purchase price.
The 10% rate applies to the base price before GST. For a net price of $100, GST is $10, making the gross total $110. To reverse-calculate: divide the GST-inclusive price by 11 to get the GST amount.
How it works
Working
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GST tip: Australian GST is a flat 10%. Businesses with GST turnover ≥ $75,000 must register.
| Net | GST | Gross |
|---|---|---|
| $10 | $1 | $11 |
| $50 | $5 | $55 |
| $100 | $10 | $110 |
| $500 | $50 | $550 |
Frequently Asked Questions
What is GST in Australia?
GST (Goods and Services Tax) is a 10% tax applied to most goods and services sold in Australia, introduced on 1 July 2000. It replaced several previous indirect taxes. Businesses with turnover of $75,000 or more must register for GST and collect it on behalf of the Australian Tax Office (ATO). The GST collected on sales is shown separately on invoices, and businesses can claim back the GST they pay on their own purchases through their Business Activity Statement (BAS). Most everyday items like food, healthcare, and education are either GST-free or input-taxed.
Does every business need to charge GST?
Businesses with an annual turnover of $75,000 or more are legally required to register for GST. Those below this threshold can register voluntarily, which is often beneficial if the business has significant expenses with GST (like equipment, supplies, or contractor costs) since it allows claiming input tax credits. Once registered, businesses must charge GST on all taxable supplies, charge it on invoices correctly, and lodge BAS statements (monthly, quarterly, or annually depending on turnover). Failing to register when required can result in penalties from the ATO.
How do I claim back GST?
Registered businesses claim GST credits (input tax credits) through their BAS by reporting the total GST collected on sales and subtracting the total GST paid on business purchases. The net amount is either remitted to the ATO or refunded to you. If your GST paid on purchases exceeds what you collected, you receive a refund. To claim GST credits you need a valid tax invoice for purchases over $82.50 (including GST). Keep records for at least five years. Many small businesses use a registered tax agent or accounting software to manage BAS lodgement correctly and avoid ATO penalties.
What items are GST-free in Australia?
GST-free items include fresh food (fruit, vegetables, meat, bread, dairy), most medical and healthcare services, educational courses and materials, some childcare services, international exports, and public transport. These are deliberately excluded to avoid taxing basic necessities. Note that restaurant meals are generally taxable (GST applies), but takeaway food is often GST-free. A quirk: a hot chicken from a supermarket deli may be GST-free, but a hot chicken from a restaurant is taxable. For a full list, check the ATO website or consult a tax professional, as the rules can be nuanced.
How do I calculate GST backwards from a total?
To extract the GST component from a GST-inclusive price, divide the total by 11 to get the GST amount. For example, $110 divided by 11 = $10 GST. The ex-GST (pre-tax) price is the total minus the GST: $110 minus $10 = $100. This works because the GST component represents exactly 1/11th of the GST-inclusive total when GST is 10% of the pre-tax price. You can verify: $100 plus 10% equals $110. This reverse calculation is essential for working out the true cost of goods and services when comparing prices.
Is GST included in fuel prices?
Yes, fuel prices include 10% GST. However, fuel is also subject to an excise duty (currently around 44.4 cents per litre for petrol and 49.4 cents for diesel as of 2024) which is added before GST is calculated. This means the visible fuel price already contains both the excise and GST. For every $1.60/litre petrol, approximately 44 cents is excise, then 10% GST is applied on top of that (compounding the tax), making the actual pre-tax price lower than it appears. This layered taxation structure means fuel carries a disproportionately high tax burden compared to the stated GST rate alone.
What is the difference between GST-exclusive and GST-inclusive?
GST-exclusive (ex-GST) prices are the base price of a product or service before the 10% GST is applied. GST-inclusive (inc-GST) prices include the GST already, meaning the price you see is the final amount payable. When buying for business, you often want to know the ex-GST price so you can calculate the GST component you can claim back through your BAS. For personal purchases, the inc-GST price is what you actually pay. To extract GST from an inc-GST price, divide by 11, for example, $110 inc-GST contains exactly $10 GST.