This self-employment tax calculator estimates the US self-employment tax — Social Security 12.4% (to the wage base) plus Medicare 2.9% — applied to 92.35% of net self-employment earnings, with the half-SE-tax deduction shown.

Taxable SE earnings (× 92.35%) –
Social Security part (12.4%) –
Medicare part (2.9%) –
Total SE tax –
Deductible half (income-tax deduction) –

Estimate only, for planning quarterly payments. The default wage base is the 2025 figure ($176,100) — update it for your tax year. Not included: the 0.9% Additional Medicare Tax on high earners, state taxes, QBI effects, or S-corp salary/distribution splits. This is SE tax only — federal income tax on the profit is separate.

The Tax That Makes Freelancers Both Boss and Employee

The W-2 side of the same deductions is our Paycheck Calculator. Part of our Finance Calculators collection.

Worked Example (Verified)

  • Net earnings $100,000, no W-2 wages (defaults): taxable base 100,000 × 0.9235 = $92,350 → SS 12.4% = $11,451 + Medicare 2.9% = $2,678 → SE tax $14,130, of which $7,065 is deductible against income tax
  • Why 92.35%: employees never pay FICA on the employer’s 7.65% share — the 0.9235 factor (= 1 − 0.0765) replicates that exclusion for the self-employed, who wear both hats
  • The wage-base cap binds the SS part only: at $200k net with no W-2, SS tax stops at 176,100 × 12.4% = $21,836 while Medicare’s 2.9% runs uncapped — and W-2 wages consume the cap first (the W-2 field models mixed earners)

SE Tax Discipline

  • Quarterly estimates (Form 1040-ES) — SE tax isn’t withheld; underpayment penalties accrue per quarter, not per year.
  • The deductible half reduces INCOME tax, not the SE tax itself — a consolation worth real money at your marginal rate.
  • Net earnings = Schedule C profit (revenue − expenses): every legitimate business deduction cuts SE tax AND income tax — expense tracking is doubly rewarded here.
  • S-corp election trades: salary (FICA-taxed) vs distributions (not SE-taxed) — powerful, rule-bound (reasonable compensation), and beyond this estimator.

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Frequently Asked Questions

How is self-employment tax calculated?

SE earnings = net profit × 92.35%. Social Security tax = 12.4% of that, up to the year’s wage base ($176,100 for 2025, reduced by any W-2 wages already taxed); Medicare = 2.9% uncapped. On $100,000 net: $92,350 × 15.3% = $14,130 total. This calculator splits the parts and applies the cap correctly.

Why is the SE rate 15.3%?

It’s FICA doubled: employees pay 7.65% (6.2% SS + 1.45% Medicare) and employers match 7.65% invisibly. The self-employed are both parties, so they pay 12.4% + 2.9% = 15.3% — softened by the 92.35% base reduction and the deductibility of half the tax.

What is the 92.35% adjustment?

Employees don’t pay FICA on the employer’s share of their compensation. To equalize, the self-employed compute SE tax on net earnings × (1 − 7.65%) = 92.35% — effectively excluding the “employer half” of their own pay from the base.

Does the Social Security cap consider my W-2 job too?

Yes — the wage base is per person across all work. W-2 wages taxed for SS consume the cap first; this calculator’s W-2 field reduces the room left for SE earnings accordingly (common for side-business earners, whose SE income may then owe only the 2.9% Medicare part).

Is SE tax the only tax on freelance income?

No — federal (and usually state) income tax applies on top, on the profit minus the half-SE-tax deduction and any QBI deduction. Budget roughly: SE tax from this tool + income tax at your marginal rates, paid quarterly.

Is this self-employment tax calculator free?

Yes — free, instant, no sign-up. It’s a planning estimate, not tax advice; a CPA earns their fee in the details it omits.