Side Hustle Income Planner
Estimate your monthly savings from a side hustle after taxes. Use it when launching freelance work or a part-time gig to set realistic savings and investment targets.
About this calculator
The calculator uses the formula: Monthly Savings = (hourlyRate × hoursPerWeek × weeksPerYear × (1 − taxRate) × savingsAllocation) / 12. First, gross annual income is computed by multiplying your hourly rate by hours worked per week and weeks worked per year. That figure is then reduced by the tax rate (expressed as a decimal, e.g., 25% → 0.25) to give after-tax annual income. Multiplying by the savings allocation (also a decimal) yields the annual amount you plan to save or invest. Finally, dividing by 12 converts to a monthly savings figure — a practical metric for budgeting. Self-employment income is typically subject to both income tax and self-employment tax (~15.3% in the US), so factor those in when estimating your effective tax rate for the most accurate result.
How to use
Suppose you charge $40/hr, work 10 hours/week, for 48 weeks/year, with a 30% effective tax rate and plan to save 50% of after-tax income. Gross annual income = $40 × 10 × 48 = $19,200. After-tax = $19,200 × (1 − 0.30) = $13,440. Amount saved annually = $13,440 × 0.50 = $6,720. Monthly savings = $6,720 / 12 = $560/month. That $560 could fully fund a Roth IRA in about 10 months, illustrating how small side-hustle hours compound into meaningful financial progress.
Frequently asked questions
How much of my side hustle income should I set aside for taxes?
As a self-employed individual in the US, you typically owe self-employment tax of 15.3% on net earnings plus federal income tax based on your bracket. A common rule of thumb is to set aside 25–30% of gross side-hustle income for taxes. If your main job already pushes you into the 22% or higher bracket, consider setting aside 30–35% to avoid underpayment penalties at filing time.
What is a realistic number of hours per week for a profitable side hustle?
Most people sustainably dedicate 5–15 hours per week to a side hustle without burning out or affecting their primary job. At $30–$50/hr, even 8 hours per week generates $12,000–$20,000 in gross annual income. The key is choosing work with low startup overhead — freelance writing, tutoring, or consulting — so the majority of hours are billable rather than administrative.
How can I use a side hustle income planner to reach a specific financial goal faster?
Start by entering your savings goal amount and work backward: if you need $10,000 in 12 months, you need to save roughly $833/month from your side hustle. Plug in different hourly rates and hours-per-week combinations until the monthly savings output meets that target. You can also use the planner to test how raising your rate by $5/hr — rather than working more hours — dramatically shortens your timeline while protecting your time.