Your GST Calculated
Instantly.
The fastest, most accurate GST calculator for Australian businesses. Add, remove, reverse — all at 10% ATO rate, completely free.
💡 Default is 10% — change the % field for any country or custom rate.
Calculate GST in 3 Simple Steps
No accounting knowledge needed. Just enter your amount and get your GST calculated instantly — accurate to the ATO's 10% rate every time.
Enter Your Amount
Type in any dollar amount — whether it includes GST already or not. Works for any price, invoice total, or purchase amount.
Go to Calculator →Choose Your Calculation
Select whether you want to Add GST (for quoting), Remove GST (for BAS claims), or find the GST Amount hidden in a price.
See All Options →Get Instant Results
See your GST amount, ex-GST price, and GST-inclusive total instantly. No waiting, no signup, no errors — ATO-accurate every time.
Try It Free →The 3 Formulas You Must Know
GST = $50 · Use for invoicing
Net = $500 · Use for BAS
GST = $50 · Use for credits
Full GST Formula Reference Guide
At 15%: multiply by 1.15
At 20%: multiply by 1.20
Example at 10%: $1,000 × 1.1 = $1,100
GST = $100, Total = $1,100
At 15%: multiply by 15/115
At 20%: multiply by 20/120
Example at 10%: $1,100 ÷ 11 = $100 GST
Net price = $1,000
At 15%: divide by 1.15
At 20%: divide by 1.20
Example at 10%: $1,100 ÷ 1.1 = $1,000
GST removed = $100
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Businesses Daily.
From sole traders in regional NSW to growing businesses in Melbourne — our GST calculator keeps you ATO compliant without the accountant fees. Fast, free, no signup required.
Calculate GST for Free →20+ GST Topics
Fully Covered
From basic add/remove to BAS lodgement, ATO exemptions, and GST registration — every topic an Australian business needs.
Calculate GST for Free →What Australians Say About Us
Everything About GST in Australia
The most common GST questions answered — for sole traders, small businesses, and individuals.
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