💰 Self-Employment Tax: What It Is and How Much
As a self-employed person, you pay self-employment (SE) tax in place of FICA (the Social Security and Medicare taxes split between employers and employees). The rate is 15.3% on 92.35% of your net self-employment income — 12.4% for Social Security (on income up to $176,100 in 2025) and 2.9% for Medicare (no cap, with an additional 0.9% on income over $200,000 single/$250,000 married).
You can deduct half of your SE tax from your gross income — before calculating your income tax. On $80,000 net SE income: SE tax is approximately $11,304. You deduct $5,652 from your income, reducing your federal income tax base. The deduction doesn't eliminate SE tax — it partially offsets its income tax impact.
📅 Quarterly Estimated Taxes: The Schedule
Self-employed people must pay estimated taxes four times per year — not just at April 15. Missing quarterly deadlines triggers penalties (currently 8% annualized on underpaid amounts).
| Quarter | Income Period | 2025 Deadline |
|---|---|---|
| Q1 | January–March | April 15, 2025 |
| Q2 | April–May | June 16, 2025 |
| Q3 | June–August | September 15, 2025 |
| Q4 | September–December | January 15, 2026 |
Safe harbor rule: Pay at least 100% of last year's total tax liability (110% if your prior year AGI exceeded $150,000) in equal quarterly installments, and you owe no underpayment penalty — even if you end up owing more at filing. This is the simplest approach for variable-income freelancers.
✂️ The Most Valuable Self-Employment Deductions
- Health insurance premiums: 100% of premiums for you and your family, deducted directly from income (above the line). On of the most valuable deductions available.
- Home office: Dedicated business space in your home — $5/sq ft (simplified method, max $1,500) or actual percentage of home costs
- Retirement contributions: Solo 401k up to $70,000 total or SEP IRA up to 25% of net SE income — both fully deductible and the most powerful tax reduction tool for high earners
- Vehicle: Business miles at 70 cents/mile (2025 rate) or actual expenses × business use percentage
- Technology and subscriptions: Computer, phone (business portion), software, cloud services, professional tools
- Professional development: Courses, books, conferences related to your current business
- Half of SE tax: Deduct 50% of your SE tax from income (reduces income tax, not SE tax)
Don't wait until April to organize deductions. Review and categorize expenses quarterly using Wave (free) or QuickBooks Self-Employed ($15/month). Missed deductions cannot be recovered after filing without an amended return. A 2-hour quarterly review is worth thousands per year for most self-employed people.
⚖️ When to Elect S-Corp Status
At income levels above approximately $60,000–$80,000 in net SE income, electing S-Corp status can save $5,000–$20,000+ per year in SE tax by allowing you to split income between a "reasonable salary" (subject to SE tax) and "distributions" (not subject to SE tax). The savings grow substantially with higher income.
Considerations before S-Corp election:
- Requires filing a separate corporate tax return (Form 1120-S) — typically $1,500–$3,000/year in CPA fees
- Must pay yourself a "reasonable salary" — the IRS scrutinizes S-Corps that pay artificially low salaries
- Adds payroll compliance requirements (payroll taxes, W-2 for yourself)
- Generally makes sense at $80,000+ in net SE income; strongly beneficial above $100,000