Need a quick GST calculator Australia businesses can rely on? This free tool lets you add or remove 10% GST from any amount in seconds. Whether you’re preparing an invoice, checking a supplier bill, or reconciling your BAS figures, just enter your amount and get an instant breakdown of the GST-exclusive price, the GST component, and the GST-inclusive total.
Disclaimer: This article provides general information only and does not constitute tax advice. Consult a registered tax agent for advice specific to your circumstances.
GST Calculator
How to Use This GST Calculator
Using this calculator is straightforward:
- Enter your amount in the dollar field. This can be any value – an invoice total, a product price, or a lump-sum expense.
- Choose your mode. Select “Add GST” if you have a GST-exclusive amount and need to calculate the total including GST. Select “Remove GST” if you have a GST-inclusive amount and need to find out how much of it is GST.
- Read the results. The calculator instantly shows the GST-exclusive price, the GST component (10%), and the GST-inclusive total.
For example, if you enter $500 with “Add GST” selected, you’ll see that the GST is $50.00 and the inclusive total is $550.00. Switch to “Remove GST” with $550 entered, and the calculator works backwards to show the $500 base price and $50 GST component.
Understanding GST in Australia
The Goods and Services Tax (GST) is a broad-based 10% tax on most goods, services, and other items sold or consumed in Australia. It was introduced on 1 July 2000 and is administered by the Australian Taxation Office (ATO).
If your business is registered for GST, you charge GST on your sales (that’s the GST you collect) and you can claim credits for the GST included in the price of goods and services you purchase for your business. These credits are called GST credits or input tax credits, and they reduce the amount of GST you owe to the ATO.
The core GST formulas are simple:
- Adding GST: Multiply the GST-exclusive price by 1.1. A $100 item becomes $110 including GST.
- Removing GST: Divide the GST-inclusive price by 11 to find the GST component. From a $110 total, the GST is $10.
For a full overview of how GST works, see the ATO’s GST guide.
When Do You Need to Register for GST?
Not every business needs to charge GST. You must register for GST if:
- Your business has a GST turnover of $75,000 or more per year (based on current or projected turnover).
- Your non-profit organisation has a GST turnover of $150,000 or more per year.
- You provide taxi or ride-sharing services (such as driving for Uber, Ola, or DiDi) – you must register for GST regardless of your turnover.
You can also choose to register voluntarily even if your turnover is below the threshold. Some businesses do this to claim GST credits on their purchases, which can be worthwhile if you have significant business expenses. However, voluntary registration means you must charge GST on all your taxable sales and lodge Business Activity Statements, so it adds an administrative obligation.
To register, you’ll need an Australian Business Number (ABN). You can register for GST through the ATO online, by phone, or through your registered tax agent.
GST and Your BAS
Once you’re registered for GST, you report your GST figures through your Business Activity Statement (BAS). Most small businesses lodge their BAS quarterly, though some lodge monthly or annually depending on their turnover and circumstances.
Your BAS captures two key GST numbers:
- GST on sales (1A): The total GST you’ve collected from customers on your taxable sales during the period.
- GST on purchases (1B): The total GST you’ve paid on business purchases during the period. These are your GST credits.
The difference between these two figures determines whether you owe the ATO a payment or receive a refund. If you collected more GST than you paid, you owe the difference. If you paid more GST on purchases than you collected on sales – common for new businesses or those with large capital expenses – the ATO refunds the difference to you.
Keeping accurate, up-to-date records of every transaction and its GST component throughout the quarter is what makes BAS lodgement smooth. When your records are messy or incomplete, BAS preparation becomes a time-consuming scramble that increases the risk of errors and missed credits.
For more on staying organised for BAS, see our guide on GST receipt tracking for BAS.
Track GST Automatically with Taxr
Manually calculating GST on every receipt and expense gets tedious fast, especially when you’re dealing with dozens of transactions each week. That’s where Taxr comes in.
Taxr’s AI-powered receipt scanner automatically extracts the GST amount from every receipt you scan. Just snap a photo of your receipt, and Taxr reads the total, identifies the GST component, and categorises the expense – all in seconds. No manual data entry, no missed credits, no guesswork.
Here’s how Taxr simplifies your GST workflow:
- Automatic GST extraction – Taxr’s AI reads the GST amount directly from your receipts, so you never have to calculate it yourself.
- Organised expense categories – Every scanned receipt is categorised, making it easy to see your GST position at a glance.
- BAS-ready exports – When it’s time to lodge your BAS, export a report with your GST totals already calculated. Hand it to your accountant or use it to fill in your BAS directly.
- Never lose a receipt – Every receipt is stored digitally, so you always have proof of purchase if the ATO comes asking.
Whether you’re a sole trader tracking business expenses or a freelancer juggling multiple clients, Taxr turns GST tracking from a chore into something that just happens in the background.
Stop calculating GST manually and let Taxr handle it for you.