A W-2 stub withholds employee FICA (6.2% + 1.45%) and Publication 15-T income tax. A 1099 / Schedule C year pays both halves of Social Security and Medicare (SECA) and Form 1040 income tax. Those are different statutes. Mixing them is how people under-save for April.
On $50,000 of net earnings from self-employment, filing single, no W-2 Social Security wages, the on-site take-home engine returns:
- Self-employment tax: $7,064.78 (same as IRS Topic 554 on $50,000)
- Income tax: $3,396.11
- Combined tax: $10,460.89
- Left after those two federal pieces: $39,539.11
- Rough quarterly set-aside: $2,615.22
Run the self-employment take-home calculator →
The calculator uses SECA (IRC § 1401), the deductible one-half of SE tax (IRC § 164(f)), the 2026 standard deduction, and the Form 1040 §1 tables in Rev. Proc. 2025-32 §4.01. It does not include QBI §199A, Additional Medicare 0.9%, NIIT, credits, state tax, or retirement contributions. Not tax advice.
Why this is not a W-2 paycheck
Employee FICA on $50,000 of W-2 wages would be 7.65% = $3,825, and the employer pays another $3,825. You never see the employer half on the stub.
SECA starts from 92.35% of net earnings (Topic 554):
SECA base = $50,000 × 0.9235 = $46,175
Social Security = 12.4% × $46,175 = $5,725.70
Medicare = 2.9% × $46,175 = $1,339.08
SE tax = $7,064.78
The Social Security piece stops at the $184,500 2026 wage base (the same base as W-2). Medicare has no wage base. If you already have W-2 Social Security wages, remaining room shrinks. $180,000 already paid on a W-2 leaves $4,500 of Social Security room on the side gig.
The SECA-only tool (no income tax) is the self-employment tax calculator. This page is the stacked number: SECA plus Form 1040.
From SE tax to take-home (single, $50,000)
- Deductible half of SE tax = $7,064.78 ÷ 2 = $3,532.39 (IRC § 164(f))
- AGI used here = $50,000 − $3,532.39 = $46,467.61
- Standard deduction (single, 2026) = $16,100
- Taxable income = $46,467.61 − $16,100 = $30,367.61
- Form 1040 single table: $1,240 + 12% × ($30,367.61 − $12,400) = $3,396.11
- Total federal tax in this model = $7,064.78 + $3,396.11 = $10,460.89
- Take-home = $50,000 − $10,460.89 = $39,539.11
Married filing jointly on the same $50,000 uses the $32,200 standard deduction and Table 1 rates. Taxable income becomes $14,267.61. Income tax drops to $1,426.76. SE tax does not change with filing status.
| Filing status | SE tax | Income tax | Take-home |
|---|---|---|---|
| Single, $50,000 net | $7,064.78 | $3,396.11 | $39,539.11 |
| MFJ, $50,000 net | $7,064.78 | $1,426.76 | $41,508.46 |
| Single, $8,000 net | SECA still due | $0 | net minus SE tax only |
Low net profit can zero the income-tax line and still leave SECA. The $8,000 single case in the engine has taxable income $0 and income tax $0. Self-employment tax is still positive.
Nearby W-2 number (not the same job)
A W-2 $2,000 biweekly check ($52,000 a year), single, no 401(k), no Step 2, keeps $1,651.15 after $195.85 FIT and $153.00 employee FICA. That is the paycheck calculator default. Annual net on that path is $42,929.90.
Do not subtract $42,929.90 − $39,539.11 and call it “the 1099 penalty.” The W-2 example is $52,000 gross wages. The 1099 example is $50,000 net profit (after business expenses). Different starting points. The useful contrast is the rate stack: employee 7.65% vs SECA 15.3% on 92.35%, plus Form 1040 vs Pub 15-T.
Quarterly cash, not a W-4
There is no W-4 on self-employment. The take-home tool splits combined tax by four: $2,615.22 on the $50,000 single case. Whether that meets the safe harbor (avoid the estimated-tax penalty) is a different worksheet. Use the estimated tax safe harbor calculator. Putting a side amount on a W-2 Step 4(a) only raises that job’s withholding. It does not compute SECA. See W-4 Step 4.
Business miles are a Schedule C expense before this take-home math. 2026 has two business rates (72.5 cents, then 76 cents). See IRS standard mileage 2026 and the mileage calculator.
QBI §199A can lower income tax for some trades. Additional Medicare 0.9% can apply at high earnings (thresholds). Health insurance for the self-employed has its own deduction. None of those are in the $39,539.11 figure.
What this page is not
- Not a 50-state income-tax or LLC-fee guide.
- Not the SECA-only page. That is self-employment tax.
- Not a W-2 take-home clone. W-2: paycheck take-home.
That is SECA only (Topic 554). Single filers in this model also owe $3,396.11 of income tax on the same $50,000. Combined: $10,460.89. Credits, QBI, and itemizing can change the income-tax half.
No. That tool is employee FICA + Pub 15-T withholding. Self-employment uses SECA + Form 1040 tables. Wrong engine, wrong number.
$2,615.22 is total modeled tax ÷ 4. The penalty-avoidance test is the safe-harbor worksheet, not this split. Confirm Form 1040-ES and the safe harbor calculator.
Topic 554 · Topic 751 (FICA contrast) · Rev. Proc. 2025-32 §2.14 and §4.01 · Form 1040-ES