Self-Employment Tax:
How to Calculate and Reduce It
Self-employment tax is 15.3% applied to 92.35% of your net business profit, because you pay both halves of Social Security and Medicare that an employer would otherwise split with you. Here is exactly how to calculate it, the wage-base cap and 0.9% surtax, and the two legitimate ways to pay less.
How self-employment tax is calculated
Self-employment (SE) tax funds Social Security and Medicare for people who work for themselves. Because no employer is paying half for you, you owe the full 15.3% — 12.4% Social Security plus 2.9% Medicare. The key wrinkle: it applies to 92.35% of your net profit, not the whole amount. You figure it on Schedule SE, and you get to deduct half of it.
- Start with your net profit (business income minus deductions) from Schedule C.
- Multiply net profit by 92.35% — this is your "net earnings from self-employment."
- Apply 12.4% (Social Security) up to the 2026 wage base of $184,500, and 2.9% (Medicare) on the whole amount with no cap.
- Add the 0.9% Additional Medicare Tax on earnings over $200,000 (single) / $250,000 (MFJ) if it applies.
- Deduct half of the SE tax above the line on your Form 1040.
What self-employment tax is and why it exists
When you work a W-2 job, Social Security and Medicare come out of every paycheck as FICA. You pay 7.65% and your employer quietly pays the matching 7.65% — you never see it. When you work for yourself, there is no employer to pay that other half, so you pay both halves. That combined 15.3% is self-employment tax.
It is not a penalty and it is not income tax. It funds the exact same Social Security and Medicare benefits a W-2 worker earns. The shock for most contractors is simply that the second half was always being paid on their behalf, and now they see the full bill.
Self-employment tax is figured on Schedule SE and added to your income tax on Form 1040. For how it fits into your overall 1099 filing, see our 1099 contractor taxes guide.
| W-2 employee | Self-employed | |
|---|---|---|
| Your share | 7.65% | 15.3% |
| Employer share | 7.65% (employer pays) | None — you pay it all |
| How it is collected | Withheld each paycheck | Schedule SE, paid quarterly |
| Applied to | Gross wages | 92.35% of net profit |
The rate breakdown: 15.3% on 92.35% of profit
The 15.3% splits into two parts: 12.4% for Social Security and 2.9% for Medicare. But you do not apply it to your full net profit. First you multiply net profit by 92.35%, then apply the rates to that smaller number.
The 92.35% factor exists to mirror the W-2 world. An employee's wages do not include the employer's share of FICA, so to keep self-employed people on equal footing the law lets you remove the equivalent (the 7.65% employer-half) from the base before the tax is figured. 100% minus 7.65% leaves 92.35%.
In plain terms: every $100 of net profit is treated as $92.35 of "net earnings from self-employment," and the 15.3% lands on that.
The wage-base cap and the 0.9% high-earner surtax
No. The two pieces of SE tax behave differently at the top. The 12.4% Social Security portion stops at the annual wage base. For 2026 the Social Security wage base is $184,500 (up from $176,100 in 2025). Above that, you pay no more Social Security tax for the year.
The 2.9% Medicare portion has no cap. It applies to every dollar of net earnings, no matter how high. So once you pass the wage base, your marginal SE-tax rate drops from 15.3% to 2.9%.
High earners pay one more layer: the 0.9% Additional Medicare Tax on earnings above $200,000 (single), $250,000 (married filing jointly), or $125,000 (married filing separately). It stacks on top of the 2.9% Medicare for income over those thresholds.
| Net earnings band | Social Security 12.4% | Medicare 2.9% | Add'l Medicare 0.9% |
|---|---|---|---|
| Up to $184,500 | Yes | Yes | No |
| $184,500 – threshold | No (capped) | Yes | No |
| Over $200k / $250k | No (capped) | Yes | Yes |
The 50% self-employment tax deduction
You get to deduct half of your self-employment tax as an adjustment to income on Form 1040. This restores the parity that the 92.35% factor started: a W-2 employee never pays income tax on the employer half of FICA, so you should not either.
It is an above-the-line deduction, meaning you take it whether or not you itemize, and it comes off before your income-tax bracket is applied. It lowers your income tax, not your SE tax — the SE tax itself is already calculated. A lot of contractors filing on their own miss it entirely.
Worked examples at two income levels
The math is identical every time: net profit × 92.35% × the rates. The only thing that changes at higher income is that the 12.4% Social Security piece stops at $184,500 while the 2.9% Medicare piece keeps going. Two examples make it concrete.
Notice in the second example that the effective rate falls. Once net earnings cross the wage base, every additional dollar is taxed at only 2.9% (plus the 0.9% surtax once you clear $200k/$250k), not the full 15.3%.
Who owes self-employment tax: the $400 rule
If your net earnings from self-employment are $400 or more for the year, you must file a return and pay self-employment tax on them. This is true even if you would not otherwise have to file based on income tax alone. The $400 is figured after the 92.35% reduction.
It applies to sole proprietors, single-member LLCs, independent contractors, gig workers, and partners in a partnership. It does not apply to your W-2 wages — those already had FICA withheld. Below $400 of net self-employment earnings, you generally owe no SE tax, though you may still owe income tax.
How to pay less self-employment tax (legally)
1. Maximize legitimate deductions. SE tax is figured on net profit, so every real business deduction lowers the base it is calculated on. Tools, vehicle expenses, the home office, and supplies all reduce SE tax directly, not just income tax. The first lever is simply not overstating your profit.
2. Retirement contributions reduce income tax, not SE tax. A SEP-IRA or Solo 401(k) is a powerful tool, but be clear-eyed: those contributions lower your income tax, not the SE tax itself (SE tax is figured before them). They are still worth it — just not an SE-tax dodge.
3. The S-corp election — the real SE-tax lever. If your net profit is high enough, electing S-corp status lets you split income into a reasonable W-2 salary (which carries payroll tax) and distributions (which do not carry SE or payroll tax). That distribution portion escapes the 15.3%. As a rough EA rule of thumb, the savings start to outweigh the added cost and complexity somewhere around $45,000–$75,000 of net profit — but the exact breakeven depends on your numbers and needs a consultation. We walk through the full decision in our LLC vs. S-corp for contractors guide.
Frequently Asked Questions
Stop overpaying your self-employment tax.
We work only with contractors. Book a free 30-minute call and we will run your numbers — including whether an S-corp election would cut your 15.3% bill.
