Self-Employment Tax Explained: The 15.3% Freelancers Owe

Why freelancers owe an extra 15.3% — and the deductions and quarterly rules that soften it.

By Colson, Founder, ColsonSuperApps LLC · 6 min read

The first time you file as a freelancer, the tax bill can be a shock. On top of regular income tax, the self-employed owe self-employment (SE) tax — and it catches a lot of new contractors off guard.

Why it exists

When you're a W-2 employee, your employer quietly pays half of your FICA taxes — 6.2% Social Security and 1.45% Medicare — and you pay the other half. When you work for yourself, you are both the employer and the employee, so you pay both halves: 15.3% total (12.4% Social Security + 2.9% Medicare).

What it applies to

SE tax is calculated on 92.35% of your net business income (gross income minus business expenses), not the full amount. The Social Security portion only applies up to the annual wage base; the Medicare portion has no cap, and high earners pay an extra 0.9% above a threshold.

The deductions that soften it

  • Half of SE tax is deductiblefrom your income before income tax is figured — it doesn't reduce the SE tax itself, but it lowers your income-tax bill.
  • Business expenses reduce net income directly, so good bookkeeping pays off.
  • The QBI deduction can cut up to 20% of qualified business income from your taxable income.
  • Retirement plans (SEP-IRA, Solo 401k) shelter more income than a regular IRA.

Quarterly estimated payments

There's no employer withholding tax for you, so the IRS expects quarterly estimated payments. Setting aside roughly 25–30% of net income is a common starting point, but your real rate depends on your bracket and state.

Estimate yours

The self-employment tax calculator estimates your SE tax, income tax, take-home, and quarterly set-aside from your net business income and state. Tracking expenses across the year is what makes that number smaller — accounting tools like QuickBooks automate it.

Try it with your numbers: the free paycheck calculator shows your exact take-home after federal, state, and FICA taxes — instantly, in your browser.

Educational only — not tax, legal, or financial advice.