GST CALCULATOR AUSTRALIA

Use our free GST calculator to quickly add GST, remove GST (ex GST),or perform a reverse GST calculation — ideal for Australian invoices, quotes, receipts and simple business pricing. This Australian GST calculator supports GST-inclusive and GST-exclusive amounts so you can move between before GST and including GST in seconds.

Add or remove GST in real time. Default rate 10%.

GST in Australia is 10%. Some supplies are GST-free.
GST Amount
$0.00
Amount ex-GST
$0.00
Amount inc-GST
$0.00

What this GST calculator can do

  • Add GST (convert ex GST → inc GST)
  • Remove GST / ex GST calculator (inc GST → ex GST)
  • Reverse GST calculator (find GST component + base amount)
  • GST inclusive and GST exclusive pricing checks
  • GST amount calculator (GST portion for reporting)

How to use (2 steps)

Step 1: Choose your mode — Plus GST (add) or Minus GST (remove / excluding GST).
Step 2: Enter your amount to instantly see GST value, total inc GST, and total ex GST (depending on mode).

Common use cases: quotes, invoices, shopping receipts, service fees, contractor charges and basic bookkeeping.

GST (Australia) explained — simple, practical

GST is a goods and services tax applied to many products and services in Australia. When you see a price including GST, the GST portion is built into the total. When a price is shown excluding GST (ex GST), GST is added on top.

When to use “Add GST”

Use add GST calculator mode when you have an ex GST price and need the final amount including GST (for example, a supplier price list or a service quote).

  • Ex GST → Inc GST totals
  • Show GST separately on invoices

When to use “Remove GST”

Use remove GST calculator mode when the amount already includes GST and you need the ex GST amount (e.g., for bookkeeping, expense claims or comparing supplier pricing).

  • Inc GST → Ex GST breakdown
  • Extract GST component from receipts
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Note: This calculator is designed for quick GST maths. For complex tax situations, check ATO guidance or speak with a registered tax agent.

FAQs

How do I add GST to a price in Australia?

Use Plus GST mode. Enter the ex GST amount and the calculator will show the GST amount and the total including GST.

How do I remove GST (ex GST) from an amount?

Use Minus GST / Remove GST mode. Enter the GST-inclusive total and the calculator will extract the ex GST amount and the GST component.

What is a reverse GST calculation?

A reverse GST calculator breaks a GST-inclusive total into two parts: the ex GST base amount and the GST amount. It’s useful when you only have the total from a receipt or invoice.

What’s the difference between GST inclusive and GST exclusive?

GST inclusive means the price already includes GST in the total. GST exclusive (ex GST) means GST is added on top. This GST calculator lets you switch between both.

Is this an ATO GST calculator?

This is a free calculator built by Australia Pay Calculator for quick GST maths. For official GST rules and eligibility, refer to ATO guidance.

Can I use this GST calculator for invoices and quotes?

Yes — it’s ideal for checking GST on quotes, invoices and receipts, and for working out GST amounts for basic reporting.

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