How to Calculate GST in Australia:
The Complete 2026 Guide
Everything Australian businesses, freelancers and consumers need to know about GST calculations — adding it, removing it, reverse calculating it, and understanding which goods are exempt. Updated for 2026 ATO requirements.
What is GST in Australia?
GST (Goods and Services Tax) is a broad-based tax of 10% on most goods, services and other items sold or consumed in Australia. It was introduced on 1 July 2000 by the Howard Government and has remained at 10% ever since.
GST is collected by businesses on behalf of the government. When you sell a taxable product or service, you add 10% GST to your price, collect that amount from your customer, and then pass it on to the Australian Taxation Office (ATO) via your Business Activity Statement (BAS).
How to Add GST to a Price (GST-Exclusive to GST-Inclusive)
Use this method when you know the price before GST and want to find the final price customers pay.
GST-Inclusive Price = Price × 1.1
Step-by-Step Example: Adding GST
Start with your price before GST
You're charging $350 for a service. This is your GST-exclusive (ex-GST) amount.
Calculate the GST amount
$350 × 0.10 = $35 GST
Calculate the total price including GST
$350 × 1.1 = $385.00 (inc. GST)
Invoice your customer
Show both the ex-GST amount ($350), GST amount ($35) and total ($385) on your tax invoice.
How to Remove GST from a Price (GST-Inclusive to GST-Exclusive)
Use this method when you know a price that already includes GST and need to find the original pre-tax amount.
GST-Exclusive Price = Price ÷ 1.1
Example: Removing GST
You receive a receipt for $220 and need to separate the GST component:
- GST-exclusive amount: $220 ÷ 1.1 = $200.00
- GST amount charged: $220 ÷ 11 = $20.00
- Verify: $200 + $20 = $220 ✓
Reverse GST Calculation Explained
Reverse GST (also called "working backwards from GST") is when you have a GST-inclusive total and want to know the original price and GST breakdown. This is especially useful when:
- Checking whether a supplier has charged GST correctly
- Claiming GST credits (input tax credits) on business purchases
- Reconciling receipts for your BAS lodgement
- Pricing your own services to achieve a specific after-GST total
Original Price (ex-GST) = Total ÷ 1.1
GST Component = Total ÷ 11
Check: ex-GST + GST = Total ✓
Real-World GST Calculation Examples
Here are common scenarios Australian businesses and individuals face:
| Scenario | Amount | Ex-GST | GST | Inc-GST |
|---|---|---|---|---|
| Freelance invoice | $1,000 ex | $1,000.00 | $100.00 | $1,100.00 |
| Retail product | $55 inc | $50.00 | $5.00 | $55.00 |
| Restaurant bill | $88 inc | $80.00 | $8.00 | $88.00 |
| Consulting day rate | $2,000 ex | $2,000.00 | $200.00 | $2,200.00 |
| Monthly subscription | $49.50 inc | $45.00 | $4.50 | $49.50 |
| Tradesperson quote | $850 ex | $850.00 | $85.00 | $935.00 |
The quickest mental check: a GST-inclusive price should always be exactly 10% higher than the ex-GST price. If $1,000 becomes $1,100 — you've added GST correctly. If something doesn't add up, use our free calculator to verify instantly.
GST-Free Items and Exemptions in Australia
Not everything attracts GST. The ATO divides supplies into three categories:
1. Taxable Supplies (10% GST applies)
Most goods and services sold in Australia — clothing, electronics, tradesperson services, restaurants, ride-sharing, professional services.
2. GST-Free Supplies (0% GST, but credits can be claimed)
| Category | Examples | Status |
|---|---|---|
| Basic foods | Bread, milk, fresh fruit & vegetables, meat, eggs | GST-Free |
| Medical services | GP visits, hospital care, ambulance services | GST-Free |
| Education | School fees, university courses, childcare | GST-Free |
| Exports | Goods sold to overseas customers | GST-Free |
| Certain medicines | Prescription drugs listed on the PBS | GST-Free |
| Menstrual products | Tampons, pads, menstrual cups | GST-Free |
| Restaurants & cafes | Hot food, coffee, dine-in meals | Taxable |
3. Input-Taxed Supplies (no GST, no credits)
- Residential rent — you don't charge GST on rent and can't claim credits
- Financial services — loans, insurance, credit cards
- Precious metals — gold, silver bullion in certain conditions
Who Must Register for GST in Australia?
You must register for GST with the ATO if:
- Your annual GST turnover is $75,000 or more
- Your non-profit organisation's turnover is $150,000 or more
- You provide taxi, limousine or ride-share services (Uber, Didi, etc.) — regardless of turnover
- You want to claim fuel tax credits
Once registered, you must lodge BAS statements quarterly (or monthly if your turnover exceeds $20 million) and remit net GST to the ATO by the due date.
Frequently Asked Questions About GST in Australia
Is GST the same as VAT?
Yes, GST and VAT (Value Added Tax) are essentially the same concept — a consumption tax collected at each stage of production and distribution. Australia uses the term GST, while the UK and EU use VAT. Australia's GST rate (10%) is lower than most VAT rates around the world.
What's the difference between GST-inclusive and GST-exclusive pricing?
GST-inclusive means the price shown already has GST added — the customer pays that amount. GST-exclusive means GST hasn't been added yet — B2B pricing is often quoted exclusive of GST so businesses can compare true costs before tax.
Can I claim back GST on all business purchases?
You can claim back GST (input tax credits) on purchases you make for your business, provided the purchase relates to your taxable activities, you are registered for GST, and you hold a valid tax invoice. You cannot claim credits on private or personal purchases, or on purchases relating to input-taxed supplies.
What happens if I charge GST but forget to register?
If you're required to be registered for GST but aren't, you'll owe the ATO all the GST that should have been collected — even if you didn't charge it to your customers. You may also face penalties and interest charges. Register as soon as your turnover reaches $75,000.
Do I charge GST on overseas clients?
Generally, services exported to overseas clients are GST-free provided the supply is made to a non-resident who is outside Australia at the time of supply. However, the rules are complex — always confirm with the ATO or a tax agent for international transactions.