Free browser tool
GST Calculator Australia
Estimate Australian GST from a base price or back out GST from a total price.
!
This calculator is for estimates only. Verify the GST treatment for your exact business situation before filing or invoicing.
Calculator
Results update as you type
Tax amount
$13.00
Total price
$113.00
Tax rate
13%
Example
Australian GST planning keeps the math simple: it shows the before-tax and after-tax values instantly in the browser.
Formula
The math behind the result
GST amount = base price × GST rate. Total = base price + GST amount. Reverse mode finds the base from the GST-inclusive amount.
How it works
A clean flow from input to answer
- 1Enter your base price or GST-inclusive price.
- 2Set the tax rate to the amount you want to model.
- 3Read the GST amount and total instantly.
FAQ
Common questions
Does it support reverse calculations?
Yes. It can work backwards from a GST-inclusive total.
Does the calculator save my inputs?
No. Everything happens locally in the browser.
Can I use it on mobile?
Yes. It is built to stay readable on smaller screens.
Is this an accounting system?
No. It is a fast planning calculator, not a full tax workflow.
Can I use it for quotes?
Yes. It is practical for quote and invoice planning.