GST Calculator Australia: Add or Remove 10% GST, BAS & Tax Invoices
GST Calculator Australia
Goods and Services Tax is the 10% tax built into many Australian goods and services. If you need a fast number, use the GST Calculator to add 10% GST, remove GST from a total, or check the GST component before you issue a quote, invoice or Business Activity Statement (BAS).
This guide explains the practical parts behind GST-inclusive and GST-exclusive prices, tax invoices, GST credits and BAS reporting for Australian businesses.
Add or remove 10% GST
The two common GST calculations are:
| Scenario | Formula | Example |
|---|---|---|
| Add GST to a GST-exclusive price | price x 1.1 | $100 becomes $110 |
| Remove GST from a GST-inclusive price | total / 1.1 | $110 becomes $100 |
| Find the GST component in an inclusive price | total / 11 | $110 includes $10 GST |
That last formula is useful when a supplier gives you a GST-inclusive total and you need to split out the GST amount for records or BAS preparation.
GST-inclusive and GST-exclusive prices
Australian business quotes and invoices often use one of three price styles:
- GST-exclusive: the listed amount is before GST, so 10% is added at the end.
- GST-inclusive: the listed amount already includes GST.
- Plus GST: a common shorthand meaning the amount is GST-exclusive.
For example, a $1,000 consulting fee plus GST becomes a $1,100 invoice total. A $1,100 GST-inclusive total contains $100 GST and $1,000 before GST.
GST registration threshold
The standard $75,000 GST registration threshold applies when your GST turnover is $75,000 or more in a year. Not-for-profit organisations generally use a $150,000 threshold. Taxi, limousine and ride-sourcing drivers usually need GST registration regardless of turnover.
Once registered, you normally add GST to taxable sales, lodge activity statements, pay net GST to the Australian Taxation Office, and claim GST credits for creditable business purchases.
BAS and GST credits
A Business Activity Statement (BAS) reports GST collected on sales and GST paid on business purchases. The basic BAS flow is:
| BAS item | What it means |
|---|---|
| GST on sales | GST you collected from customers |
| GST credits | GST you can claim back on eligible business purchases |
| Net GST | GST on sales minus GST credits |
If GST on sales is higher than your credits, you pay the difference. If credits are higher, the amount may reduce what you owe or create a refund, depending on the rest of the activity statement.
Keep tax invoices, receipts and records that support the amounts you claim. A calculator helps with arithmetic, but your records need to show what happened.
Tax invoice checks
A tax invoice usually needs enough detail for the buyer and seller to identify the supply, price and GST treatment. Before sending or recording one, check:
- The supplier identity and ABN are correct.
- The invoice says tax invoice where required.
- The total price and GST amount are clear.
- Line items show whether prices are plus GST or GST-inclusive.
- The calculation matches 10% GST for taxable supplies.
For quick invoice checks, enter the GST-exclusive or GST-inclusive total in the GST Calculator and compare the GST component with your invoice line items.
GST-free and input-taxed sales
Not every sale has GST added. Some supplies are GST-free, such as many basic foods, certain health services, education courses and exports. Some supplies are input-taxed, including many financial supplies and residential rent.
These categories affect whether GST is charged and whether credits can be claimed. If your business has mixed sales or complex transactions, use the calculator for the simple arithmetic and confirm the treatment with your accountant or the ATO.
Example GST invoice
Suppose a designer charges $850 plus GST:
| Line | Amount |
|---|---|
| Design fee before GST | $850 |
| GST at 10% | $85 |
| Invoice total | $935 |
If a customer pays $935 and you are registered for GST, the $85 GST component is not ordinary income to keep. It is part of the GST amount that may be reported through BAS after allowing for any GST credits on eligible business expenses.
Tools and resources
Use these PayCal tools together when you are preparing business paperwork:
- GST Calculator for GST-inclusive, GST-exclusive and GST component checks
- Invoice Generator for PDF tax invoices with ABN, GST, payment terms and logo support
- Quote Generator for quotes that can include GST, discounts and valid-until dates
- Contractor Pay Calculator for contractor income scenarios that may be plus GST or GST-inclusive
Final tips
- Confirm whether every price is plus GST or GST-inclusive before comparing totals.
- Register for GST when your turnover reaches the required threshold or your business type requires it.
- Keep tax invoices and receipts before claiming GST credits.
- Reconcile GST before lodging BAS so sales, purchases and credits match your records.
Need a quick Australian GST check? Use the GST Calculator to add GST, remove GST, and verify the GST component before you finish your quote, invoice or BAS.