The first year I filed as self-employed, I opened my tax software, saw the SE tax line, and assumed something was broken. Fourteen thousand dollars on top of income tax? For Social Security and Medicare I was supposedly already covered? Nobody had explained the 92.35 percent thing to me. This article is the explanation I wish someone had handed me.
The short answer
On $100,000 of net self-employment profit in 2026, you owe $14,130 in self-employment tax. That is an effective rate of 14.1 percent on your profit, and half of it, $7,065, is deductible on your income tax return.
The long answer, line by line
Self-employment tax is 15.3 percent: 12.4 percent for Social Security plus 2.9 percent for Medicare. But it does not apply to your full $100,000. Here is the sequence Schedule SE actually runs:
| Step | Calculation | Result |
|---|---|---|
| 1. Net profit | Schedule C, line 31 | $100,000 |
| 2. Taxable SE earnings | $100,000 x 92.35% | $92,350 |
| 3. Social Security tax | $92,350 x 12.4% (below the $184,500 wage base) | $11,451 |
| 4. Medicare tax | $92,350 x 2.9% (no cap) | $2,678 |
| 5. Total SE tax | $11,451 + $2,678 | $14,130 |
| 6. Deductible half | $14,130 / 2, Schedule 1 line 15 | $7,065 |
Step 2 is the one that confuses everyone. The 92.35 percent factor exists because employees split FICA with their employer, and the employer half never gets taxed. The IRS gives the self-employed an equivalent break by taxing only 92.35 percent of net earnings. It comes from IRC section 1402(a)(12), and it is the reason the effective rate on your profit is 14.13 percent rather than the full 15.3.
What changes at higher incomes
At $200,000 of profit, the taxable base is $184,700. That is just above the $184,500 Social Security wage base, so the 12.4 percent portion maxes out at $22,878 while Medicare keeps going: $184,700 times 2.9 percent is $5,356. Total SE tax: $28,234.
At $300,000 of profit, the base is $277,050. Social Security is still capped at $22,878. Medicare is $277,050 times 2.9 percent, or $8,034. Then the additional Medicare tax kicks in: earnings above $200,000 for a single filer get hit with another 0.9 percent, which adds roughly $693 on the $77,050 over the threshold. Total: about $31,606.
Notice what happens as income rises. The Social Security piece flattens at $22,878 and the whole thing starts to feel like just the Medicare tax plus a bit. This is exactly why high earners start asking about S-corp elections: the savings concentrate above the wage base.
The mistake I see most
People budget for income tax and forget SE tax exists until April. If you are self-employed and expect to owe at least $1,000 in total tax, the IRS wants quarterly estimated payments: April 15, June 15, September 15, and January 15. On $100,000 of profit, the SE tax portion alone is about $3,532 per quarter, and that is before income tax.
My rule of thumb for the first two years: set aside 30 percent of every payment you receive, in a separate account, the day it arrives. You will over-save some quarters. That is the point. The pain of over-saving is nothing next to the pain of a surprise five figure bill plus an underpayment penalty.
Run your exact profit
Enter your net profit, W-2 wages, and filing status for the full breakdown and quarterly amounts.
Open the Self-Employment Tax CalculatorRelated reading: Self-Employment Tax vs Income Tax: What Each One Actually Pays For.
Not tax advice. Figures use 2026 rates: $184,500 Social Security wage base, 15.3 percent SE rate, 92.35 percent base.