Calculator Form
Plotly Graph
This chart compares the GST-exclusive subtotal, GST amount, and GST-inclusive total for the latest calculation.
Example Data Table
| Scenario | Mode | Entered Amount | GST Rate | GST Amount | Final Total |
|---|---|---|---|---|---|
| Single product sale | Exclusive | AUD 100.00 | 10% | AUD 10.00 | AUD 110.00 |
| Bundle with shipping | Exclusive | AUD 185.00 | 10% | AUD 18.50 | AUD 203.50 |
| Invoice already includes GST | Inclusive | AUD 220.00 | 10% | AUD 20.00 | AUD 220.00 |
| Find GST inside paid total | Extract | AUD 55.00 | 10% | AUD 5.00 | AUD 55.00 |
Formula Used
1) Add GST to a tax-exclusive amount
Tax-exclusive subtotal = (Unit Price × Quantity) + Shipping + Extra Fee − Discount
GST Amount = Tax-exclusive subtotal × GST Rate
GST-inclusive total = Tax-exclusive subtotal + GST Amount
2) Remove GST from a GST-inclusive amount
GST-inclusive total = (Unit Price × Quantity) + Shipping + Extra Fee − Discount
GST-exclusive subtotal = GST-inclusive total ÷ (1 + GST Rate)
GST Amount = GST-inclusive total − GST-exclusive subtotal
3) Find the GST portion inside a total
GST Amount = GST-inclusive total × [GST Rate ÷ (1 + GST Rate)]
GST-exclusive subtotal = GST-inclusive total − GST Amount
This calculator assumes the discount is applied to the entered amount before the final GST split or addition is completed.
How to Use This Calculator
- Choose whether you want to add GST, remove GST, or isolate the GST portion.
- Enter the unit price and quantity for the product or order.
- Add shipping, extra fees, and any discount applied to the transaction.
- Confirm the GST rate. Australia commonly uses 10% for standard taxable sales.
- Select the rounding precision that matches your invoice or store policy.
- Click the calculate button to show the result above the form.
- Use the CSV button for spreadsheets or the PDF button for printable records.
- Review the chart and example table to compare how GST changes totals.
FAQs
1. What does this Australia GST calculator do?
It calculates GST-exclusive amounts, GST amounts, and GST-inclusive totals for ecommerce orders. It also handles quantity, shipping, extra fees, discounts, custom GST rates, and rounding.
2. What GST rate is commonly used in Australia?
The standard GST rate in Australia is generally 10% for many taxable goods and services. This tool starts with 10% but lets you change the rate when needed.
3. Can I remove GST from a price that already includes tax?
Yes. Choose the GST-inclusive removal mode. The calculator will split the entered total into the GST-exclusive subtotal and the GST component automatically.
4. Can I include shipping and service fees?
Yes. You can enter shipping and extra fees as part of the transaction. The tool includes them in the entered total before the GST calculation is finalized.
5. How are discounts handled?
The discount is subtracted from the entered total before the final GST addition or GST split is calculated. This helps model common ecommerce invoice workflows.
6. Why does the chart matter?
The chart makes it easier to compare the tax-exclusive subtotal, GST amount, and final total. It gives a quick visual check for pricing, invoice review, and margin planning.
7. What is the CSV export useful for?
CSV export is useful when you want to keep a spreadsheet-ready record of the calculation. You can store, sort, or share the breakdown in accounting or reporting workflows.
8. Can I save the result as a PDF?
Yes. The PDF button creates a downloadable summary from the current result section. It is helpful for invoices, internal checks, and client-facing tax documentation.