# GST Calculator Australia 2026 — Add or Remove 10%

Source page: https://valem.run/calculators/australia/vat

Australian GST is 10%, fixed by section 9-70 of the GST Act 1999. Because the rate is a tenth, the GST inside a GST-inclusive price is exactly one eleventh of it.

**Tax year:** 2026

## How it is calculated

The rate on this page comes from the **statute itself**, not from a summary of it. Section 9-70 of the *A New Tax System (Goods and Services Tax) Act 1999* reads: *"The amount of GST on a taxable supply is 10% of the value of the taxable supply."* The figure is quoted from the compilation in force on 1 January 2026.

One tenth going on means **one eleventh coming off**, and that is the single most useful fact about Australian GST. A $110 tax-inclusive price contains $10 of GST: divide by 11, not by 10. Dividing by 10 is the common error and overstates the GST by a tenth.

This page covers the **rate only**, and the omission is deliberate. Australia does have a registration turnover threshold — section 23-15 of the Act creates one — but the Act leaves the *amount* to be prescribed by regulation, so the $75,000 figure that is widely quoted is not established by the Act, and the ATO’s own website refuses automated requests. Rather than publish a figure on trust, this page states the rate it can source and says plainly what it cannot. GST-free supplies — most basic food, health and education — carry no GST at all, which is a different mechanism from a reduced rate and so is not offered here as a band you can select.

## Worked example

With Amount of 100, this model computes Vat Amount of 10.

## Inputs

| Name | Label | Type |
| --- | --- | --- |
| `amount` | Amount | number |
| `direction` | Direction | string |
| `reverseCharge` | B2B reverse charge applies | boolean |

## Sources

- [Federal Register of Legislation - GST Act 1999 s 9-70 (10%)](https://www.legislation.gov.au/C2004A00446/latest/text) (checked 2026-10-05)

## What this page claims

The Valem engine reproduces this model's formula through 4 self-test cases. That shows internal consistency, not that the formula matches current law; the cited sources are the evidence for that. Estimate, not tax advice.

## For agents

- Model manifest (formula, constants, test vectors): https://valem.run/calculators/australia/vat.json
- Compute by URL: https://valem.run/calculators/australia/vat.json?amount=100
- MCP: https://valem.run/mcp/calculators (call `calculate` with calculator `australia/vat`)