GST Calculator
Add or remove Australian GST at 10%.
Result
- Ex GST
- $10,000.00
- GST
- $1,000.00
- Inc GST
- $11,000.00
FREE AUSTRALIAN GST CALCULATOR
GST Calculator
Quickly add 10% Australian GST to an ex-GST amount or separate the GST component from an inclusive amount. It is designed as a simple arithmetic aid for construction and project cost checks.
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When this tool is useful
Practical preliminary checks
- Checking supplier or subcontractor amounts before and after GST
- Reviewing project cost schedules that mix inclusive and exclusive amounts
- Checking progress-claim or variation arithmetic
- Converting a GST-inclusive total to the underlying ex-GST amount
How it works
To add GST, the ex-GST amount is multiplied by 1.10. To remove GST from an inclusive amount, the total is divided by 1.10. The GST component is the difference between the inclusive and exclusive amounts.
Important estimating note
This calculator only performs arithmetic using the standard 10% GST rate. It is not tax advice and does not determine whether a particular supply, transaction or entity is subject to GST.
Frequently asked questions
How do I add 10% GST?
Multiply the ex-GST amount by 1.10. The difference between the result and the original amount is the GST component.
How do I remove GST from an inclusive total?
Divide the GST-inclusive amount by 1.10 to find the ex-GST amount.
Is the GST rate in Australia 10%?
The standard Australian GST rate is 10%. Whether GST applies to a specific transaction is a tax question and may require professional advice.
Related EBC guidance
Understand the project behind the calculation
Need help applying the numbers to a real building project?
EBC works on renovations, extensions and new builds across Melbourne's Eastern Suburbs.