General information only — not financial advice for your situation.
This is a learning tool. Always check CRA My Account records and talk to a qualified professional for your own numbers.
Plain English
Here's the thing about having a side hustle on top of a regular job: Canada's tax system is progressive, so your side-hustle dollars sit on the very top of the pile and get taxed at whatever your highest rate is. If your day job pays $70,000, your side-hustle income starts getting taxed at the ~30% rate. By putting every dollar of side-hustle profit into an RRSP, you get a deduction that cancels out the tax on that income. It's like the side hustle went straight into retirement savings before the government took its cut.
Your day job pays $75,000. Your side hustle nets $15,000. That $15,000 is taxed at your top marginal rate of ~31.48% in Ontario — a $4,722 tax bill. If you contribute the full $15,000 to your RRSP, you get a $4,722 refund, completely neutralizing the tax on the side income. Net tax impact of the side hustle: $0.
Show the analysis
Side-hustle income is classified as self-employment income on the T1 and stacks above T4 employment income for marginal rate purposes. For an individual with $75,000 primary income (second federal bracket, 20.5% + 9.15% Ontario = 29.65%), additional side-hustle income between $75,000 and $107,785 faces the same 29.65–31.48% combined rate. An RRSP deduction equal to the net side-hustle income eliminates this marginal liability. The side income also generates 18% RRSP room for the following year, creating a self-reinforcing contribution cycle.
Primary salary: $75,000. Side hustle net profit: $15,000. Total income: $90,000. Marginal rate on $75K–$90K corridor (Ontario): 31.48%. Tax on side income: $15,000 × 31.48% = $4,722. RRSP contribution of $15,000: deduction saves $4,722. Net side-hustle tax: $0. Bonus: $15,000 generates $2,700 of new RRSP room (18%) for next year.
Edge cases
- If total income (salary + side hustle) remains below $58,523, the combined rate is only ~20% — consider TFSA instead to preserve RRSP room for higher-earning years.
- Self-employment income triggers both employer and employee CPP contributions (11.9%) — factor this additional cost into your side-hustle cash flow planning.
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About this site
Every number on this site is sourced from CRA publications, the Income Tax Act, or provincial fiscal releases. We show the math, cite the sources, and never tell you what to do with your money.