GST Calculator Australia
Add 10% GST to a price or take it out of a GST-inclusive total. Use the invoice tab when you have a mix of taxable and GST-free items.
Invoice Lines Calculator
Work out GST line by line when some items have GST and others are GST-free.
Invoice Summary
| Type | Amount (ex GST) | GST |
|---|
What Is GST in Australia?
Last reviewed October 2026.
GST stands for Goods and Services Tax. It is a broad tax of 10% on most goods, services and other items sold or consumed in Australia, and it is collected by the Australian Taxation Office (ATO). Australia does not have VAT. GST is Australia's version of it, and the rate is the same in every state and territory.
Businesses that are registered for GST add it to their prices, and they can claim back the GST they pay on business purchases. The tax is ultimately paid by the final customer. The calculator above does the arithmetic in either direction: adding GST to a price, or working out how much GST is already inside a price.
How to Calculate GST
Because the rate is a flat 10%, there are only three sums you need. Pick the one that matches the price you have.
Price with GST = price × 1.1
GST = price × 0.1
GST = price with GST ÷ 11
Price without GST = price with GST ÷ 1.1
Adding GST: examples
| Price Excluding GST | GST (10%) | Price Including GST |
|---|---|---|
| $50.00 | $5.00 | $55.00 |
| $100.00 | $10.00 | $110.00 |
| $250.00 | $25.00 | $275.00 |
| $500.00 | $50.00 | $550.00 |
| $1,000.00 | $100.00 | $1,100.00 |
| $5,000.00 | $500.00 | $5,500.00 |
Removing GST: examples
| Price Including GST | GST Inside (÷ 11) | Price Excluding GST |
|---|---|---|
| $55.00 | $5.00 | $50.00 |
| $110.00 | $10.00 | $100.00 |
| $220.00 | $20.00 | $200.00 |
| $1,000.00 | $90.91 | $909.09 |
| $2,500.00 | $227.27 | $2,272.73 |
A Common Mistake When Taking GST Out
Say you paid $110 including GST. Many people take 10% of $110 and call that the GST. That is wrong, because the 10% was charged on the original price, not on the total.
$110 × 10% = $11 GST, so the price without GST is $99.
$110 ÷ 11 = $10 GST, so the price without GST is $100.
The calculator uses the correct method, so choose Remove GST whenever you start from a GST-inclusive total.
What Does GST Apply To?
Not everything you buy carries 10% GST. In general, supplies fall into three groups:
Whether a particular item is taxable, GST-free or input-taxed depends on ATO rules. Check the ATO website if you are unsure. The Invoice Lines tab lets you mark each line as GST (10%) or GST-free.
Do I Need to Register for GST?
You must register for GST if your business has a GST turnover of $75,000 or more. For non-profit organisations the threshold is $150,000. Turnover means your business sales (not profit), and the test looks at both the last 12 months and your expected next 12 months. Once you reach or expect to reach the threshold, you generally need to register within 21 days.
- Taxi and ride-sourcing drivers must register for GST regardless of turnover.
- Below the threshold, registration is optional. Registering lets you claim GST credits on business purchases, but you must then charge GST on your sales.
- Use the ATO's guidance or a registered tax agent to confirm your own turnover and the date you must register.
GST Credits and Your BAS
Registered businesses report GST on their Business Activity Statement (BAS). You pay the ATO the GST you collected from customers, minus the GST credits you can claim on eligible business purchases.
Example: one quarter
- Sales, GST included: $11,000, so GST collected = $11,000 ÷ 11 = $1,000
- Purchases, GST included: $3,300, so GST credit = $3,300 ÷ 11 = $300
- GST payable to the ATO: $1,000 − $300 = $700
If your GST credits are bigger than the GST you collected, you may get a refund instead.
Tax Invoices and the $82.50 Rule
If you are registered for GST and make a taxable sale of $82.50 or more (including GST), you must give the customer a tax invoice when they ask for one. For sales over $1,000, the invoice must also identify the buyer, for example by name or ABN. A buyer generally needs a valid tax invoice to claim a GST credit on a purchase over $82.50.
A proper tax invoice shows the seller's ABN and states that it is a tax invoice, and it shows the GST amount or says the total includes GST. The ATO sets the full list of required details, so check them before you issue invoices.
GST on Overseas and Online Purchases
GST can apply to goods and digital services bought from overseas sellers, and many large overseas sellers collect it at checkout when they sell to Australian customers. The rules depend on the value of the goods and who the seller is, so confirm the current position on the ATO website before relying on a figure.
Is GST the Same in Every State?
Yes. GST is a national tax, so it is 10% in New South Wales, Victoria, Queensland, South Australia, Western Australia, Tasmania, the ACT and the Northern Territory. Unlike stamp duty, it does not change from state to state. You do not need a separate calculator for each state.
GST vs VAT: Are They the Same?
VAT and GST are both consumption taxes that work in the same way, with businesses collecting the tax and claiming credits on what they buy. The main difference is the name and the rate. Australia uses GST at 10%, while countries such as the UK use VAT at other rates. If you were looking for a VAT calculator for another country, that tool lets you pick the rate.
How This GST Calculator Works
The calculator uses the three formulas above with a fixed 10% rate. On the Invoice Lines tab, each line is rounded to the nearest cent and then added together. If you enter prices that already include GST, GST-taxable lines are divided by 1.1, and GST-free lines are left alone.
Different accounting packages can round on the invoice total rather than each line, which can leave a one-cent difference. Both are generally acceptable, but follow the method your accountant or software uses.
Frequently Asked Questions
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This page gives general information only and is not tax, legal or financial advice. GST rules, thresholds and exemptions can change, and your circumstances may differ. Check current details with the Australian Taxation Office or a registered tax agent before you make a decision. Last reviewed October 2026.