What This Tool Does
The Australian Side Hustle Tax Calculator is a free online tool that helps you estimate the additional tax you'll owe when earning income outside of your regular employment. Whether you drive for Uber, sell on Etsy, freelance, do consulting, rent on Airbnb, or run any other side business, this calculator gives you a clear picture of your tax position.
Unlike generic income tax calculators, this tool is specifically designed around the most common question Australians with side hustles ask: "I already earn a salary — how much extra tax will I owe on top of that?"
FY 2025–26 ATO Rates
Uses current Australian tax brackets, Medicare levy thresholds, and LITO offsets — updated annually.
GST Threshold Alerts
Flags when your revenue approaches or exceeds the $75,000 GST registration threshold.
HECS/HELP Impact
Shows how additional side hustle income increases your compulsory HECS repayment amount.
Quarterly Instalments
Breaks your tax liability into quarterly PAYG instalment estimates with actual ATO due dates.
Deductions Support
Enter your claimable expenses to calculate tax on your actual profit, not gross revenue.
100% Private
All calculations happen in your browser. No data is collected, stored, or transmitted.
Frequently Asked Questions
Do I need to declare my side hustle income to the ATO?
Yes. If your side hustle is a business (not a hobby), all income must be declared in your annual tax return regardless of how small the amount. The ATO receives data from banks, payment platforms (PayPal, Stripe, Square), and online marketplaces, making undeclared income increasingly easy for them to detect.
Why is tax higher on my side hustle than on my salary?
Your employer's PAYG withholding assumes your job is your only income source. Side hustle income is added on top, pushing you into a higher tax bracket. Your effective marginal tax rate on side hustle income is therefore higher than your average rate on your salary — often 32–47% depending on your combined income level.
Do I need an ABN for my side hustle?
If you're running a genuine business (issuing invoices, operating commercially), you should register for an ABN. Without one, clients are required by law to withhold 47% of any payment to you and remit it to the ATO. ABN registration is free and takes minutes at abr.gov.au.
When do I need to register for GST?
You must register for GST once your side hustle revenue reaches $75,000 in any 12-month rolling period. Once registered, you charge an additional 10% GST on sales and lodge quarterly Business Activity Statements (BAS) with the ATO. The $75,000 threshold applies to revenue (not profit), so deductions don't reduce it.
What expenses can I claim as deductions?
Any expense that is directly related to earning your side hustle income may be deductible. Common deductions include: phone and internet (business proportion), equipment and tools, software subscriptions, home office expenses, vehicle costs (with a logbook), advertising and marketing, and accountant fees. Keep receipts for everything.
Is this a hobby or a business?
The ATO distinguishes between hobbies (not taxable, no deductions) and businesses (taxable income, deductions allowed). Key indicators of a business include: intention to make a profit, repeated and regular activity, operating in a business-like manner, and selling to the general public. The ATO has a tool to help you decide.
How accurate is this calculator?
This tool provides estimates based on standard 2025–26 ATO individual tax rates. It does not account for all possible offsets, surcharges, or individual circumstances — such as private health rebates, dependent children, investment losses, or complex business structures. Always consult a registered tax agent for advice specific to your situation.
Disclaimer
This calculator is provided for informational and educational purposes only. It is not financial, tax, or legal advice. Results are estimates based on 2025–26 ATO tax rates and do not account for all individual circumstances. Always consult a registered tax agent or accountant before making financial decisions. The Australian Taxation Office website at ato.gov.au is the authoritative source for Australian tax information.
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