The Simple Version

Self-employment tax is basically Social Security and Medicare tax for people who work for themselves. When you're an employee, your employer pays half and you pay half. When you're self-employed, you pay both halves.

The rate: 15.3% on your net self-employment income (that's 12.4% for Social Security + 2.9% for Medicare)


Why Does It Exist?

When you're a W-2 employee, you might notice these deductions on your pay stub:

Social Security: 6.2% (you) + 6.2% (employer) = 12.4% total

Medicare: 1.45% (you) + 1.45% (employer) = 2.9% total

When you're self-employed, there's no employer to pay the other half—so you pay the full 15.3% yourself. That's self-employment tax.


How It's Calculated

Here's the step-by-step:

  1. Start with net self-employment income (revenue minus business expenses)
  2. Multiply by 92.35% (this accounts for the "employer half" deduction)
  3. Calculate Social Security: 12.4% on income up to $0
  4. Calculate Medicare: 2.9% on all income
  5. Add them together = your SE tax

Example: $80,000 Net Income

Net SE Income $80,000
× 92.35% $73,880
Social Security (12.4%) $9,161
Medicare (2.9%) $2,143
Total SE Tax $11,304

The Good News: Deductions

Self-employed people get some tax breaks to help offset the SE tax:

1. Half of SE Tax is Deductible

You can deduct 50% of your self-employment tax from your income. This reduces your income tax (though not your SE tax itself).

2. QBI Deduction (20%)

The Qualified Business Income deduction lets you deduct up to 20% of your business income. Learn more about QBI →

3. Health Insurance Deduction

If you pay for your own health insurance, you can deduct 100% of the premiums.

4. Retirement Contributions

SEP IRAs and Solo 401(k)s let you save for retirement and reduce your taxable income. Learn more about SEP IRAs →


Additional Medicare Tax

High earners pay an extra 0.9% Medicare tax on self-employment income above:

  • $200,000 (single)
  • $250,000 (married filing jointly)

Don't Forget Quarterly Payments

Unlike W-2 employees who have taxes withheld each paycheck, self-employed people need to pay estimated taxes quarterly. If you don't, you could face penalties.

Learn about quarterly taxes →


Calculate Your SE Tax

SE Tax Calculator → Quarterly Tax Calculator

Related Topics

Disclaimer

This article is for informational and educational purposes only and does not constitute tax advice. Self-employment tax rules can be complex. Consult a qualified tax professional for advice specific to your situation.