GST Calculator
Quickly add or remove Australia's 10% Goods and Services Tax from any amount, whether you're pricing an invoice or working out what tax is hiding in a receipt.
Built and checked byTimothy Hirou GaschereauFigures verified at the source on
Your details
Price including GST
$110
Price excluding GST
$100
GST (10%)
$10
Price including GST
$110
Uses the standard Australian GST rate of 10%. Some supplies are GST-free or input-taxed (like most basic food, health and education), in which case this calculator doesn't apply. Not tax advice, check ato.gov.au or speak with a registered tax agent for your specific situation.
How to use this calculator
- 1. Select 'Add GST' for a GST-exclusive price, 'Remove GST' to find the tax hiding in a GST-inclusive price, or 'BAS estimate' to work out your net GST for the quarter.
- 2. For add or remove, enter the price you're starting with. For a BAS estimate, enter your total GST-inclusive sales and business purchases.
- 3. See the GST-exclusive price, GST amount and GST-inclusive price, or in BAS mode, the GST you've collected, the credits you can claim, and the net amount to pay or be refunded.
How GST actually works in Australia
GST (Goods and Services Tax) is a broad-based 10% consumption tax on most goods and services sold or consumed in Australia. It's been 10% since it was introduced on 1 July 2000, and it hasn't budged since. GST-registered businesses collect it on the ATO's behalf, then hand it over (minus GST credits for what they've paid on business purchases) through a Business Activity Statement, usually lodged quarterly.
Not everything attracts GST. Some sales are GST-free (no tax charged, but the seller can still claim credits) and some are input-taxed (a different treatment again). For everything else, GST is effectively a tax on the end consumer, businesses in the middle of the supply chain aren't out of pocket for it.
The two GST calculations you need
Every GST calculation comes down to one of two jobs: adding GST to a price, or pulling the GST back out of a price that already includes it. Mixing the two up is the single most common GST mistake people make.
Adding GST to a GST-exclusive price
Multiply by 1.1. That adds exactly 10% to the base price. If you need the GST amount on its own, multiply the ex-GST price by 0.1, then add it back to get the total.
Removing GST from a GST-inclusive price (the divide-by-11 rule)
This is where people trip up. If you already have a GST-inclusive total and need to find the GST hiding inside it, you don't divide by 10. You divide by 11. GST is 10% of the ex-GST price, not 10% of the total, so on a $110 price the $10 of GST is 10/110 of the total, which simplifies to 1/11. Divide by 10 instead and you get $11 on that same $110, overstating the GST by a dollar. On a $10,000 invoice, that error becomes $909. To find the ex-GST price directly, divide the inclusive price by 1.1.
Worked examples
Say you're a sole trader quoting a job that costs $350 before GST. Add GST to price it up for the invoice, then work backwards from the total to double-check.
| Step | Calculation | Result |
|---|---|---|
| GST-exclusive price | - | $350.00 |
| GST amount (add) | $350.00 x 0.1 | $35.00 |
| GST-inclusive price | $350.00 x 1.1 | $385.00 |
| GST amount (remove) | $385.00 / 11 | $35.00 |
Your invoice goes out at $385.00, of which $35.00 is GST. Work backwards from that $385.00 receipt and you land on exactly the same $35.00 GST and $350.00 ex-GST price. That's the check to run whenever you want to be sure you've used the right formula.
Who needs to register for GST
Registration is compulsory once your GST turnover (gross business income, not profit) hits the threshold, and voluntary below it. Taxi and ride-sourcing drivers, think Uber, must register regardless of turnover, before their first trip.
| Business type | Registration threshold |
|---|---|
| Most businesses and sole traders | $75,000 GST turnover |
| Non-profit organisations | $150,000 GST turnover |
| Taxi and ride-sourcing drivers | No threshold, register from day one |
Once you know you've crossed, or will cross, the threshold, you've got 21 days to register. Miss that window and the ATO can chase you for GST on sales from the date you should have registered, even on sales where you never collected it from customers, so it comes straight out of your own pocket. Running a side hustle that's creeping toward this mark? Our guide to the $75,000 GST threshold and the 21-day rule goes into more detail, and our piece on whether you need an ABN for a side hustle is worth reading first, since you'll need one before you can register for GST.
What's GST-free
GST-free means no GST is charged on the sale, but the seller can still claim GST credits on their inputs. The main categories are:
- Basic food, most fresh, frozen, dried or canned fruit and vegetables, raw meat and fish, eggs, unflavoured milk, plain bread, rice and flour. Confectionery, soft drinks, flavoured drinks, sports drinks, crisps and other savoury snacks all still attract GST, so a plain bread roll is GST-free but a bag of chips isn't.
- Health services, medical, dental, physiotherapy, optometry, nursing, psychology and chiropractic services when they're a listed health service provided by a recognised professional and generally accepted as necessary treatment.
- Education, tertiary courses from registered providers, first aid and lifesaving courses, and eligible adult and community education courses.
- Exports and international travel, goods exported from Australia and international travel are generally GST-free too.
When in doubt on a specific item, the ATO's own lists are the definitive word, not this page or any other calculator online.
FAQ
What is the GST rate in Australia?
10%. It's a flat rate applied to most taxable goods and services sold or consumed in Australia, and it's been 10% since GST was introduced on 1 July 2000. It hasn't changed since.
How do I add GST to a price?
Multiply the GST-exclusive price by 1.1. For example, $200 x 1.1 = $220, with the $20 difference being the GST. If you only need the GST amount on its own, multiply the ex-GST price by 0.1. Enter your amount above and pick "Add GST" and the calculator does this instantly.
How do I calculate the GST component from a GST-inclusive price?
Divide by 11, not 10. For example, $220 divided by 11 is $20 of GST. To find the ex-GST price, divide by 1.1 instead: $220 divided by 1.1 is $200. This is what the "Remove GST" mode above does, sometimes called a reverse GST calculator or GST-inclusive calculator.
Why do I divide by 11 and not 10 to remove GST?
Because GST is 10% of the ex-GST price, not 10% of the total. If the ex-GST price is $100, GST is $10 and the total is $110. That $10 is 10/110 of the total, which simplifies to 1/11. Dividing by 10 instead gives you $11, overstating the GST by a dollar on every $110, and the gap only gets bigger on larger invoices.
What is the GST registration threshold in Australia?
$75,000 in GST turnover a year for most businesses and sole traders, $150,000 for non-profits. Taxi and ride-sourcing drivers must register regardless of turnover. Once you cross the threshold, you have 21 days to register, and missing that window can mean the ATO backdating GST you owe.
What food items are GST-free in Australia?
Most basic, unprocessed food is GST-free: fresh and frozen fruit and vegetables, raw meat and fish, eggs, unflavoured milk, plain bread, rice and flour. Confectionery, soft drinks, flavoured drinks, sports drinks, crisps and other savoury snacks still attract GST. Check the ATO's detailed food list if you're unsure about a specific item.
Are health services GST-free in Australia?
Many are, but not all. Medical, dental, physiotherapy, optometry, nursing, psychology and chiropractic services are GST-free when they're a listed health service provided by a recognised professional and generally accepted as necessary treatment. Cosmetic procedures that aren't medically necessary are generally taxable.
What is the difference between GST-inclusive and GST-exclusive prices?
A GST-exclusive price (also called the ex-GST or net price) is the price before GST is added. A GST-inclusive price is the total the end consumer actually pays, GST already baked in. Business invoices often show both figures side by side, while prices advertised to consumers are generally required to be GST-inclusive.
Can I claim GST credits on business purchases?
Yes, if you're registered for GST, you can generally claim back the GST you paid on purchases used in your business, known as GST credits or input tax credits. You claim them on your Business Activity Statement, offsetting the GST you've collected from customers. You can't claim credits if you're not registered, or the purchase is private or relates to input-taxed sales.
What happens if I don't register for GST when I should?
The ATO can require you to pay GST on your taxable sales from the date you should have registered, even if you never collected it from customers, so it comes straight out of your own revenue, plus possible penalties and interest. Register as soon as you know you've crossed the threshold, don't wait for the end of the financial year.
Is GST the same as sales tax in other countries?
It's similar in concept to a VAT (value-added tax) used in the UK, EU and elsewhere, but the exact rates, exemptions and rules differ by country. Don't assume figures from another country's calculator apply here.
Related reading
Side Hustle Tax in Australia: What You Actually Have to Declare
Earned money from Airbnb, Uber or freelancing? All side hustle income is taxable in Australia. The ATO rules, hobby vs business test, and what to claim.
Do You Need an ABN for Your Side Hustle? (The ATO's Real Test)
No income threshold triggers an ABN. The ATO uses a multi-factor business test. Exactly when you need an ABN for your Australian side hustle.
GST Registration in Australia: The $75,000 Threshold and the 21-Day Rule
When does the $75,000 GST registration threshold apply in Australia? The 21-day rule, ATO penalties, and when voluntary registration makes sense.
Where these numbers come from
Every rate and threshold in this calculator was read off the official page, not copied from another calculator. Check them yourself, they change.
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Disclaimer
This calculator uses the standard Australian GST rate of 10%. It doesn't account for GST-free or input-taxed supplies, which are treated differently and don't have GST added or removed the same way. This tool provides estimates only, is not tax advice, and doesn't replace advice from a registered tax agent or ato.gov.au.