GST Calculator Australia

Need a quick GST calculator Australia businesses can rely on? This free tool adds or removes 10% GST from any amount. Use it when you're preparing an invoice, checking a supplier bill or reconciling your BAS figures: enter the amount and you get the GST-exclusive price, the GST component and the GST-inclusive total straight away.

Disclaimer: This article provides general information only and does not constitute tax advice. Consult a registered tax agent for advice specific to your circumstances.

This calculator has no year-specific rates: it uses the 10% GST rate.

How to Use This GST Calculator

Using this calculator is straightforward:

1. Enter your amount in the dollar field. This can be any value, such as an invoice total, a product price or a lump-sum expense.
2. 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.
3. 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 or DiDi), whatever 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. Taxr does that part for you.

Taxr's AI receipt scanner reads the GST amount from every receipt you scan. Snap a photo of the receipt and, in about 5 seconds, Taxr reads the vendor, date, total and GST component and suggests a category. You check the details and save, with nothing to type in.

Here's how Taxr helps with GST:

• Automatic GST extraction: Taxr's AI reads the GST amount directly from your receipts, so you don't have to calculate it yourself.
• Organised expense categories: Every receipt gets a category, and your export totals the GST you've paid in each one.
• Exports for BAS time: When it's time to lodge, export your receipts for the quarter to Excel or PDF with the GST on your purchases already totalled. Email it to your accountant or use it for the GST credits (1B) on your BAS.
• Never lose a receipt: Every receipt you scan is stored in your Taxr account, so you have proof of purchase if the ATO asks.

For a sole trader tracking business expenses or a freelancer with several clients, that means GST credits get recorded as you spend, not pieced together at the end of the quarter.

Stop working out GST by hand. Start free and let Taxr read it from your receipts.

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