Skip to main content
AussieCalc

GST Calculator

Add or remove 10% Australian GST from any price (results update as you type).

When to use

When you need to add GST to a quote or extract the GST component from an amount that already includes tax.

Who it's for

Business owners, contractors, and freelancers issuing or reviewing Australian tax invoices.

What you'll need

Just a dollar amount, the calculator handles the 10% calculation instantly.

Australian GST at 10%

Enter a price without GST (calculate the GST and total).

$

Enter any dollar amount.

Quick presets

Australian GST rate is 10%. Results rounded to the nearest cent. General guidance only — not financial or tax advice.

GST in Australia

How GST works in Australia

The Goods and Services Tax (GST) is a broad-based 10% tax on most goods and services sold in Australia. It was introduced on 1 July 2000. GST is collected by registered businesses at each step of the supply chain, but ultimately paid by the end consumer. If you are a GST-registered business, you charge GST on taxable sales and claim credits (input tax credits) for the GST included in your business purchases. The net amount (GST collected minus credits) is reported and paid to the ATO via your Business Activity Statement (BAS).

Adding vs removing GST

Adding GST means multiplying a GST-exclusive price by 1.1 to get the total including GST. For example, $100 × 1.1 = $110. Removing GST means dividing a GST-inclusive total by 1.1, or equivalently multiplying by 10/11. On a $110 invoice, the pre-GST amount is $100 and the GST is $10. A common shortcut: the GST component of any GST-inclusive price is always 1/11th of the total. This is because GST is calculated as 10% of the pre-GST price, and the pre-GST price is 10/11ths of the total.

GST-free and input taxed supplies

Not everything attracts GST. GST-free supplies include most basic food items (fresh fruit, bread, milk), many medical and healthcare services, educational courses, and exports. Input taxed supplies — such as residential rent and most financial services — also don't charge GST, but businesses making these supplies generally cannot claim input tax credits on related purchases. A common mistake is assuming all food is GST-free: takeaway food, restaurant meals, confectionery, and ice cream are taxable. When in doubt, check the ATO's GST food guide.

GST registration threshold

You must register for GST if your business has a GST turnover of $75,000 or more in a 12-month period ($150,000 for non-profit organisations). If you are a taxi, limousine, or ride-sharing driver, you must register regardless of turnover. Registering below the threshold is optional but can be advantageous if you have significant GST-inclusive business expenses you want to claim as input tax credits. Once registered, you must lodge a BAS (monthly, quarterly, or annually) and remit any net GST to the ATO.

Common GST mistakes

Dividing by 10 instead of 11

On a $110 total, $110 ÷ 10 = $11 is wrong. The correct GST is $110 ÷ 11 = $10. GST is 10% of the pre-GST price, not 10% of the GST-inclusive total, so the divisor is 11, not 10.

Multiplying to remove GST

Multiplying a GST-inclusive price by 1.1 adds more GST on top. To recover the pre-GST price, divide by 1.1 (or multiply by 10/11). On $110 inc. GST: $110 ÷ 1.1 = $100.

Assuming all food is GST-free

Basic groceries (such as fresh produce, bread, milk, eggs), are GST-free. Restaurant meals, takeaway food, hot drinks, confectionery, ice cream, and snack foods attract GST at 10%. The boundary is counterintuitive in some cases.

Not separating GST on a tax invoice

GST-registered businesses must show the GST amount (or a statement that the price includes GST) on every tax invoice. Omitting this makes it difficult for customers to claim input tax credits.

Worked examples

Retail purchase

A coffee machine is priced at $329.00 excluding GST.

Price ex. GST
$329.00
GST (10%)
$32.90
Total inc. GST
$361.90

Verify: $361.90 ÷ 11 = $32.90 ✓

Business invoice

A graphic designer invoices a client for services at $2,400.00 ex. GST.

Service fee ex. GST
$2,400.00
GST (10%)
$240.00
Invoice total
$2,640.00

Verify: $2,640.00 ÷ 11 = $240.00 ✓

Contractor receipt

A plumber charges $550.00 including GST. What is the GST component?

Total inc. GST
$550.00
GST (÷ 11)
$50.00
Pre-GST amount
$500.00

Verify: $500.00 × 1.1 = $550.00 ✓

Frequently asked questions

What is the GST rate in Australia?
Australia's GST rate is 10%. It has been 10% since GST was introduced on 1 July 2000. The rate applies to most goods, services, and other items sold or consumed in Australia. Some supplies are GST-free (0% rate) or input taxed, meaning no GST is charged, but the headline rate for taxable supplies remains 10%.
How do I add GST to a price?
To add GST, multiply the GST-exclusive amount by 1.1. For example, $250 × 1.1 = $275. The $25 difference is the GST. Alternatively, calculate 10% of the price and add it: $250 × 10% = $25, then $250 + $25 = $275. On a tax invoice, the GST-exclusive price and the GST amount must be shown separately for invoices over $1,000.
How do I remove GST from a price?
To remove GST from a GST-inclusive total, divide by 1.1. For example, $275 ÷ 1.1 = $250 (the pre-GST price). The GST component is the difference: $275 − $250 = $25. A quick mental shortcut: the GST is always 1/11th of the GST-inclusive price. So $275 ÷ 11 = $25 GST.
What goods and services are GST-free?
GST-free items include: most basic foods (fresh produce, bread, dairy, eggs, meat); most medical and health services; most educational courses at Australian universities, TAFE, and schools; exports of goods and services; and some childcare services. Taxable food includes restaurant meals, takeaway food, confectionery, soft drinks, alcohol, snack foods, and health foods. When uncertain, use the ATO's GST food guide or consult your registered tax agent.
Do I have to register for GST?
You must register for GST if your business turnover reaches $75,000 in any 12-month period ($150,000 for non-profits). Ride-sharing and taxi drivers must register regardless of turnover. If you are below the threshold, registration is optional — but registering lets you claim input tax credits on GST-inclusive business expenses, which can be beneficial if you have high costs. Once registered, you must charge GST on taxable sales and lodge a Business Activity Statement (BAS) regularly.
Is GST the same as VAT?
GST and VAT (Value Added Tax) are economically equivalent: both are a percentage tax on consumption collected at each stage of the supply chain. Australia calls it GST; most European countries call it VAT. The key difference is the rate: Australia's GST is 10%, while European VAT rates typically range from 15% to 27%. The mechanism is the same: businesses charge the tax, claim credits for tax they paid on inputs, and remit the net amount to the government.
Why do I divide by 11 to find the GST, not 10?
Because GST is 10% of the pre-GST price, not 10% of the total. If the pre-GST price is P, then the GST-inclusive total is P + 0.1P = 1.1P. The GST is 0.1P = total × (0.1/1.1) = total ÷ 11. Dividing by 10 is a common shortcut that gives the wrong answer: on a $110 total, $110 ÷ 10 = $11 (wrong); $110 ÷ 11 = $10 (correct).
What must a valid tax invoice include?
A tax invoice must include: the words 'Tax Invoice' prominently displayed; the seller's name and ABN; the date of issue; a description of the goods or services; and the GST amount, or a statement that the total includes GST. For invoices over $1,000, the buyer's name and address are also required. Simplified tax invoices (without a buyer name) are acceptable for amounts under $1,000. Invoices under $82.50 (inc. GST) do not need to be formal tax invoices, though you should keep receipts.
What is a BAS and when do I need to lodge one?
A Business Activity Statement (BAS) is a form lodged with the ATO that reports GST collected on sales, GST credits (input tax credits) claimed on business purchases, and the net GST payable or refundable. If you are registered for GST, you must lodge a BAS regularly, the default frequency is quarterly, though businesses with GST turnover above $20 million must lodge monthly, and smaller businesses can apply for annual lodgement. BAS can be submitted online via the ATO Business Portal, myGov, or accounting software such as Xero or MYOB. The quarterly BAS is typically due 28 days after the end of the quarter (e.g., 28 October for the July–September quarter), with extended deadlines if you use a registered tax agent. Late lodgement attracts failure-to-lodge penalties, so keep a calendar reminder for each due date.

How this calculator works

The calculator handles three related GST tasks. Adding GST multiplies your amount by 1.1, giving you the GST-inclusive price. Removing GST divides by 1.1, not subtracting 10%, which is a common error that produces the wrong answer. Finding the GST component alone is calculated as the inclusive price divided by 11, because GST is always exactly one-eleventh of the total amount charged.

Australia's GST rate has been a flat 10% since 2000. The calculator applies this rate to the full amount entered, which assumes your supply is fully taxable. Basic food, medical services, education, and residential rent are GST-free or input-taxed and fall outside this calculation. If your transaction involves mixed supplies or you are unsure of the GST status of a specific item, check with the ATO or your accountant.

For business use: the GST you collect from customers is not income, it is a liability owed to the ATO and must be remitted through your Business Activity Statement (BAS). The GST you pay on business expenses is an input tax credit that reduces what you owe. Use this tool for quick mental checks or invoice calculations, but rely on ATO-registered accounting software for your BAS lodgement.

Methodology

  • Assumptions: Standard 10% GST rate applies to the full amount; supply is taxable (not GST-free or input-taxed).
  • Calculation: Add GST = amount × 1.1; remove GST = amount ÷ 1.1; GST component of an inclusive price = price ÷ 11.
  • Limitations: Does not handle mixed supplies, input-taxed financial services, GST-free supplies (food, medical, education), or cross-border digital services.

Sources

Last updated: June 2026

What to do next