Side Hustle Income Allocator
Allocate your side hustle earnings across taxes, business costs, and personal spending with a single calculation. Ideal for freelancers and gig workers managing income from multiple sources.
About this calculator
Running a side hustle means handling self-employment taxes and deductible expenses before you see spendable income. The calculator first subtracts your monthly business expenses from your gross side income to find net business income: Net Income = monthlySideIncome − businessExpenses. It then removes your combined tax burden — your income tax bracket rate plus the self-employment tax rate (typically 15.3% in the US) — to find after-tax income: After-Tax = Net Income × (1 − taxBracket − selfEmploymentTax/100). Finally, it applies a 70% discretionary spending cap, reserving the remaining 30% for savings and emergency funds: Spendable = After-Tax × 0.70. This ensures you never accidentally spend money earmarked for quarterly estimated taxes or reinvestment.
How to use
Say your side hustle earns $2,000/month with $300 in business expenses. You're in the 22% tax bracket and owe 15.3% self-employment tax. Step 1 — Net business income: $2,000 − $300 = $1,700. Step 2 — Total tax rate: 0.22 + 0.153 = 0.373. Step 3 — After-tax income: $1,700 × (1 − 0.373) = $1,700 × 0.627 = $1,065.90. Step 4 — Apply 70% discretionary cap: $1,065.90 × 0.70 = $746.13. You have approximately $746 to spend or reinvest, with $319.77 set aside for savings and future taxes.
Frequently asked questions
How much of my side hustle income should I set aside for self-employment taxes?
Self-employed individuals in the US owe the full 15.3% self-employment (SE) tax on net earnings — covering both employee and employer portions of Social Security and Medicare. You can deduct the employer-equivalent half (7.65%) when calculating your adjusted gross income. On top of SE tax, you owe regular income tax at your marginal rate. As a rule of thumb, setting aside 25–30% of every side hustle payment covers most people. Pay these quarterly to the IRS to avoid underpayment penalties.
What counts as a deductible business expense for a side hustle?
Ordinary and necessary business expenses can be deducted from your side hustle gross income, reducing your taxable profit. Common examples include software subscriptions, home office costs, equipment, professional development courses, marketing spend, and a portion of phone or internet bills. Meals and travel may be partially deductible if directly business-related. Keep receipts and use a dedicated business bank account to make record-keeping straightforward. Consult a tax professional to maximise legitimate deductions.
Why does this calculator apply a 70% spending cap to after-tax side hustle income?
The 70% cap is a guardrail that ensures you automatically reserve 30% of your after-tax side hustle earnings for savings goals and financial buffer. Many gig workers treat all post-tax income as free money and underfund their emergency fund or retirement accounts. By design, this rule forces intentional allocation before you're tempted to spend everything. You can adjust this proportion mentally — for example, splitting the 30% between a Roth IRA contribution and a three-month emergency fund top-up. It mirrors popular budgeting frameworks like the 70/20/10 rule.