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GST Calculator Australia

Free · No sign-up · Custom GST rate · Runs entirely in your browser

Add or remove 10% GST from any amount instantly, with a BAS quarterly summary and GST registration guidance.

Updated: 6 August 2026 · Reviewed by Mohsin Iqbal · 12 min read

How to add GST· How to remove GST· GST formula· BAS GST calculation
GST Calculator
Amount
$
Calculate
GST rate
%

BAS Quarterly Summary

Total GST-inclusive sales
$
Total GST-inclusive purchases
$
Result
GST Amount
ItemAmount

Estimates only, for planning purposes — not financial or tax advice. Confirm your exact GST position with the ATO or a registered tax agent.

⏱️ Last reviewed: 6 August 2026 · Written and reviewed by Mohsin Iqbal under our editorial policy and calculation methodology. Tax rules change — always confirm your position with the ATO or a registered tax agent.
📖 Approx. 12 min read💰 10% GST · 2026 ATO thresholds🔄 Updated 6 August 2026

🔑 Key Takeaways

  • GST is 10% of the price of most goods and services in Australia, unchanged since it was introduced on 1 July 2000.
  • To find the GST in a GST-inclusive price, divide by 11 — not multiply by 10%, which gives the wrong answer.
  • You must register for GST once your turnover reaches $75,000 ($150,000 for non-profits) — this threshold hasn't changed since GST began.
  • Most fresh food, health services, education and exports are GST-free; residential rent and financial services are input-taxed — these are different categories with different consequences.
  • Your BAS reconciles GST collected (G20) against GST credits on purchases (G30) — the difference is what you pay or get refunded.

Quick Answer

GST in Australia is 10%, added to most goods and services. To add GST to a price, multiply by 1.1. To find the GST already included in a price, divide by 11 — for example, $550 ÷ 11 = $50 GST, leaving $500 ex-GST. Multiplying by 10% instead of dividing by 11 is the single most common GST calculation mistake, and gives the wrong answer. Use the calculator above for instant results, including a full BAS summary.

What Is GST in Australia?

The Goods and Services Tax (GST) is a broad-based 10% consumption tax that applies to most goods and services sold or consumed in Australia. It was introduced on 1 July 2000 and has remained at 10% ever since, unlike VAT rates in many other countries which have moved over time. Registered businesses collect GST from customers and remit it to the Australian Taxation Office (ATO), reporting through a Business Activity Statement (BAS).

How to Calculate GST — Formula and Method

Add GST: Inc-GST price = Ex-GST price × 1.1
Find GST in an inclusive price: GST = Inc-GST price ÷ 11
Find the ex-GST price: Ex-GST price = Inc-GST price ÷ 1.1
General formula for any rate r: GST = Inc-GST price × r ÷ (1 + r)

The "divide by 11" rule works specifically because the GST rate is 10% — dividing by 11 is mathematically equivalent to multiplying by 10/110ths. If you're working with a different rate (say, comparing to another country's consumption tax), the calculator above generalises this correctly using the formula shown.

Step-by-Step: How to Add GST

  1. Start with your ex-GST (pre-tax) price.
  2. Multiply that price by 1.1.
  3. The result is your GST-inclusive price, ready to display or invoice.

Step-by-Step: How to Remove GST

  1. Start with your GST-inclusive total price.
  2. Divide that price by 11 to find the GST component.
  3. Subtract the GST component from the total to get your ex-GST price (or divide the total by 1.1 directly for the same result).
Example: If your invoice is $1,650 including GST, the GST is $150 ($1,650 ÷ 11) and the amount before GST is $1,500 ($1,650 − $150). Try it yourself — enter $1,650 into the calculator above with "Remove GST" selected to confirm.

The GST Formula, Summarised

GST = Inc-GST price ÷ 11 (at the standard 10% rate). This single formula covers the vast majority of everyday GST calculations — invoicing, receipts, and price checks.

BAS GST Calculation, Summarised

For your BAS: divide total GST-inclusive sales by 11 (GST collected), divide total GST-inclusive purchases by 11 (GST credits), then subtract credits from collected to find what you owe or get refunded. See the full BAS section below for the complete G1/G10/G20/G30 breakdown.

GST Inclusive vs GST Exclusive

A GST-inclusive price already has the 10% built in — this is what Australian consumers see on price tags and receipts, since businesses are required to display GST-inclusive prices to the public. A GST-exclusive price hasn't had GST added yet — this is often how businesses quote to other GST-registered businesses, since the buyer can claim the GST back as a credit anyway. Getting these two confused is a common source of pricing and invoicing errors.

Do You Need to Register for GST?

You must register for GST once your GST turnover reaches $75,000 a year ($150,000 for non-profit organisations) — a threshold that has been unchanged since GST was introduced in 2000. GST turnover is based on gross business income (before expenses), calculated on a rolling 12-month basis, looking both backward at what you've already earned and forward at what you reasonably expect to earn. Taxi and ride-sourcing drivers must register regardless of turnover, from their very first dollar of fares.

ThresholdWho It Applies To
$75,000Most businesses, sole traders, partnerships, companies and trusts
$150,000Non-profit organisations
No thresholdTaxi and ride-sourcing (rideshare) drivers

You can also register voluntarily below the threshold — worth considering if your clients are GST-registered businesses who can claim input tax credits, or if you have significant GST-inclusive business expenses you'd like to claim back.

GST on BAS — What You Need to Know

Registered businesses report GST through a Business Activity Statement (BAS), reconciling GST collected on sales against GST credits on purchases:

G1 = Total sales (inc. GST)
G10 = Total purchases (inc. GST)
G20 = GST on sales (G1 ÷ 11)
G30 = GST credits on purchases (G10 ÷ 11)
If G20 > G30 → you pay the difference. If G20 < G30 → you receive a refund.
TurnoverLodgement FrequencyDue Dates
Under $20 millionQuarterly28 days after quarter end
$20 million or moreMonthly21 days after month end
Under $75,000 (voluntary registration)Annual31 October

GST-Free and Input-Taxed Supplies

Not everything is taxed at 10% — Australian GST law has three categories, each with different consequences for businesses:

ℹ️ GST-free and input-taxed both mean "no GST charged," but they're not the same thing. The GST-credit-claiming difference matters a lot for businesses working out their actual GST position.

GST for Sole Traders and Small Business

Sole traders follow exactly the same $75,000 threshold as any other business structure — company, partnership or trust. If your turnover is below the threshold, you're not required to charge GST, but you also can't claim GST credits on your business purchases. Once registered, you need an ABN, must issue tax invoices, and take on regular BAS lodgement obligations. See our Contractor vs Employee Calculator if you're weighing up how you're classified for tax purposes more broadly, and our PAYG Withholding Calculator if you also employ staff and need to work out tax withheld from their pay alongside your GST obligations.

Tax Invoice Requirements

For GST-inclusive purchases over $82.50, you need a valid tax invoice to claim a GST credit — a standard receipt isn't enough. The tax invoice must show the supplier's ABN, a description of the goods or services, the date, the total price, and either the GST amount shown separately or a statement that the price includes GST. For supplies of $1,000 or more (GST-inclusive), the tax invoice must additionally show the buyer's identity or ABN. If you need to create compliant invoices yourself, our free Australian Invoice Builder handles the ABN format and GST fields automatically, with PDF export.

Worked Examples

TaskFormulaExample ($550 GST-inclusive)
Find GST componentPrice ÷ 11$550 ÷ 11 = $50 GST
Find ex-GST pricePrice ÷ 1.1$550 ÷ 1.1 = $500
Add GST to ex-GST pricePrice × 1.1$500 × 1.1 = $550

Common Mistakes

Frequently Asked Questions

Official Sources and References

Summary

GST in Australia is a flat 10%, unchanged since 2000. Add it by multiplying by 1.1; find it inside a price by dividing by 11, not multiplying by 10%. Registration is required once your turnover reaches $75,000 ($150,000 for non-profits), and your BAS reconciles GST collected against GST credits to determine what you pay or get refunded. Use the calculator above for instant results, including a full BAS quarterly summary.