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. Our Australian GST calculator supports GST-inclusive and GST-exclusive amounts so you can move between before GST and including GST in seconds.
GST CALCULATOR
Add or remove GST in real time. Default rate 10%.
GST Amount
Amount ex-GST
Amount inc-GST
What can GST Calculator do?
- Add GST (convert ex GST → inc GST)
- Remove GSTex GST calculator (inc GST → ex GST)
- Reverse GST calculator (find GST component + base amount)
- GST inclusive GST exclusive pricing checks
- GST amount calculator (GST portion for reporting)
How to Calculate GST in Australia
We all need to calculate GST at some point, whether we’re running a business, checking an invoice, or simply double-checking a receipt. In Australia, GST is generally 10% on most goods and services, and the calculation is simple: multiply a GST-exclusive price by 1.1 to add GST, or divide a GST-inclusive price by 1.1 to find the price before GST.
If the calculation feels confusing, don’t worry. We have helpful calculators that can do the work for you quickly and accurately.
Let’s go ahead and explore how GST is calculated, with simple examples to make it easy.
What Is GST and the Current Rate in Australia
GST stands for Goods and Services Tax. It’s a tax the government adds to most things you buy in Australia, and businesses collect it on the government’s behalf. Here’s what you need to know about the rate:
- The GST rate in Australia is a flat 10%.
- It applies to most goods, services, and other items sold or used in the country.
- A few items, like basic food, healthcare, and education, don’t carry GST at all.
- The rate hasn’t changed since GST started in July 2000.
Step-by-Step Guide GST Calculator Australia
Once you know which price you’re starting with, the calculation itself only takes a few steps.
Step 1: Check your starting price
Look at the invoice or receipt and see if it says “GST inclusive” or “GST exclusive.” Retail prices you see in shops almost always include GST already. Business quotes and wholesale prices often don’t.
Step 2: Adding GST
If you’re quoting a job or creating an invoice from a GST-exclusive price, multiply that price by 1.1. This gives you the full amount your customer needs to pay, tax included.
Step 3: Removing GST
If you have a GST-inclusive price and need to know the real cost before tax, divide it by 1.1. This is handy when you’re checking a supplier bill or working out your true profit on a sale.
Step 4: Finding the GST amount only
Sometimes you just need to know how much of a price is tax, not the whole total. Divide a GST-inclusive price by 11, or multiply a GST-exclusive price by 0.1. This is the number you’ll need when filling out your BAS.
Step 5: Check your answer
A quick way to check your work is to see if the GST amount equals exactly 10% of the price before tax. If it doesn’t match, go back and check whether you started with the right price type.
Here’s a quick cheat sheet you can save and use anytime:
What You Want to Find | Formula | Example |
Price including GST | Price × 1.1 | $200 × 1.1 = $220 |
Price excluding GST | Price ÷ 1.1 | $220 ÷ 1.1 = $200 |
GST amount (from a GST-inclusive price) | Price ÷ 11 | $220 ÷ 11 = $20 |
GST amount (from a GST-exclusive price) | Price × 0.1 | $200 × 0.1 = $20 |
Worked Examples For Easy Understanding
Numbers make this easier to picture. Here are three quick examples using the steps above.
- Adding GST: A shirt costs $200 before tax. Multiply $200 by 1.1. The price with GST is $220.
- Removing GST: An invoice shows $220 including GST. Divide $220 by 1.1. The price before tax is $200.
- Finding GST only: A receipt shows $1,000 including GST. Divide $1,000 by 11. The GST amount is $90.91.
Common GST Calculator Mistakes to Avoid
Small errors here can throw off your invoices, your books, and your tax return. Watch out for these two.
- Taking 10% off a GST-inclusive price instead of dividing by 1.1. $220 minus 10% gives you $198, not $200. That’s the wrong answer.
- Adding GST to a price that already includes it. This charges your customer GST twice and creates extra work to fix later.
Collaborate with Australia Pay Calculator
Manual math works fine for one or two invoices, but it gets old fast when you’re doing this every day. That’s where Australia Pay Calculator comes in. It takes the formulas above and does them for you, instantly and correctly, every time.
Here’s what you get:
- Instant GST results, with no formulas to remember
- One click to switch between adding and removing GST
- A tool built specifically for Australian GST rates and rules
- Free to use, with no sign-up needed
- Works on mobile, so you can check GST on the go
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.