Self-Employment Tax Calculator
The 15.3% that surprises every new freelancer — computed correctly with the 92.35% adjustment, the wage-base cap, and the deductible half.
How SE tax is computed
SE tax = base × 12.4% (up to wage cap) + base × 2.9%
Deduction: half of SE tax reduces your taxable income
Net freelance profit $70,000 (no W-2 wages):
Base: 70,000 × 0.9235 = $64,645 → Social Security 12.4% = $8,016 · Medicare 2.9% = $1,875
SE tax ≈ $9,891, of which $4,946 is deductible against income tax.
The freelancer's tax checklist
SE tax is only half the story — income tax stacks on top (estimate it with the income tax calculator, remembering the SE-tax deduction). Practical moves: pay quarterly estimates (due mid-April, June, September, and January) to avoid penalties — most freelancers set aside 25–30% of every payment; track every deductible expense since each dollar of expense saves both SE and income tax (often 30–40 cents combined); consider a Solo 401(k) or SEP-IRA, which shelters far more than employee plans; and at higher profits an S-corp election can trim SE tax on part of your income — worth professional advice once profit clears roughly $80–100k. If you also have W-2 wages, enter them above: they use up the Social Security cap first and can shrink the 12.4% portion.
$200,000 in net self-employment profit, plus $50,000 in W-2 wages from a part-time job earlier in the year:
Base: 200,000 × 0.9235 = $184,700. Social Security room left after the W-2 wages: 176,100 − 50,000 = $126,100.
Social Security portion: 126,100 × 12.4% = $15,636. Medicare: 184,700 × 2.9% = $5,356. Total SE tax ≈ $20,992.
Without the $50,000 in W-2 wages, the same $200,000 profit alone would owe about $27,193 in SE tax — the W-2 wages save roughly $6,200 by eating into the shared Social Security wage base first.
SE tax by net profit level (no W-2 wages)
| Net profit | SE tax | Effective rate |
|---|---|---|
| $40,000 | $5,652 | 14.1% |
| $70,000 | $9,891 | 14.1% |
| $100,000 | $14,130 | 14.1% |
| $150,000 | $21,194 | 14.1% |
| $200,000 | $27,193 | 13.6% |
The rate holds steady near 14.1% until net profit passes about $190,611 (the $176,100 wage base ÷ 0.9235) — the point where the 12.4% Social Security portion maxes out and only the 2.9% Medicare portion still applies above it, which is why $200,000 shows a slightly lower effective rate.
Common self-employment tax mistakes
- Forgetting W-2 wages reduce the Social Security portion. As the example above shows, $50,000 in W-2 wages saves about $6,200 in SE tax on a $200,000 self-employment profit by using up part of the shared wage base first.
- Applying 15.3% to gross revenue instead of net profit. The rate applies to net profit after business expenses, further reduced to 92.35% of that figure — a two-step reduction that's easy to miss when budgeting from top-line revenue.
- Using a flat percentage set-aside above the wage base. Once net profit crosses roughly $190,611, only the 2.9% Medicare rate still applies to the excess, so a flat 25-30% set-aside on every dollar overestimates the SE tax owed on income above that threshold.
Frequently asked questions
How much is self-employment tax?
15.3% (12.4% Social Security up to $176,100 for 2025 + 2.9% Medicare) on 92.35% of net profit, with half deductible.
Why do self-employed people pay double FICA?
You're both employer and employee, so you pay both 7.65% halves. The deduction and 92.35% adjustment soften it.
Do I need quarterly estimated taxes?
Yes if you'll owe $1,000+. Set aside 25–30% of net income and pay each quarter to avoid penalties.
How do W-2 wages interact with SE tax?
They use up the shared Social Security wage base first — $50,000 in W-2 wages saves about $6,200 in SE tax on a $200,000 self-employment profit.
Does the SE tax rate stay the same at every income level?
No — it holds near 14.1% until net profit passes about $190,611 (2025), after which only the 2.9% Medicare rate applies to the excess, lowering the overall effective rate.
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Note: Uses 2025 figures (wage base $176,100); excludes the 0.9% additional Medicare tax nuances at high incomes and state taxes. Not tax advice — consult a professional. Figures: 2025 tax year. Last reviewed: September 2026.