Self-Employment Tax Calculator — Schedule SE (2026)

How it works

The self-employed pay both halves of Social Security and Medicare — the employee share and the employer share — because there's no employer to split it with. That's why the rate is 15.3% (12.4% + 2.9%) rather than the 7.65% a wage earner sees on their own paycheck. First, net earnings are multiplied by 0.9235 (from Schedule SE): this removes the employer-equivalent share before the rate applies, so you aren't taxed on the tax. Then the 12.4% Social Security part applies only up to the annual wage base — above it, just the 2.9% Medicare continues — and high earners add 0.9% more Medicare over $200,000. Half the 15.3% tax is deductible when figuring adjusted gross income, which softens the bite.

Worked example

On $100,000 of net earnings, the SE base is $100,000 × 0.9235 = $92,350. The Social Security part is 12.4% × $92,350 = $11,451.40 and the Medicare part is 2.9% × $92,350 = $2,678.15, for $14,129.55 in self-employment tax. Half, $7,064.78, is deductible. Push net earnings to $300,000 and the base ($277,050) clears the $184,500 wage base, so the Social Security part freezes at 12.4% × $184,500 = $22,878 — only the Medicare part keeps growing.

Frequently asked questions

How is self-employment tax calculated?

Multiply net earnings by 0.9235, then apply 15.3% (12.4% Social Security up to the wage base, plus 2.9% Medicare with no cap). On $100,000 net, that's $92,350 × 15.3% = $14,129.55. It's Social Security and Medicare only — income tax is separate and computed on top.

Why 92.35% of my earnings?

Because a wage earner's employer pays half of FICA with pre-tax dollars, the self-employed get a parallel adjustment: net earnings are reduced by the 7.65% employer-equivalent share (1 − 0.0765 = 0.9235) before the 15.3% rate applies. It keeps the self-employed from paying self-employment tax on the employer-half they're covering.

Can I deduct any of it?

Yes — half of your self-employment tax is deductible when figuring adjusted gross income (not the additional 0.9% Medicare). On a $14,129.55 tax that's a $7,064.78 deduction. It lowers your income tax, not the self-employment tax itself, and you take it whether or not you itemize.

Does the Social Security part ever stop?

Yes — the 12.4% Social Security portion applies only to earnings up to the annual wage base, $184,500 in 2026, so it maxes out at $22,878. Above that, only the 2.9% Medicare portion continues, so a high earner's marginal self-employment tax drops from 15.3% to 2.9% once the cap is reached.

What about the extra 0.9% Medicare tax?

An Additional Medicare Tax of 0.9% applies to earnings above $200,000 (single) or $250,000 (married filing jointly). It's on top of the 2.9%, isn't part of the Schedule SE amount, and isn't deductible. This page shows it as a separate line; it's zero for most filers.

How does this interact with a W-2 job?

If you also have wages, they use up the Social Security wage base first, which can reduce or eliminate the Social Security part of your self-employment tax. This calculator assumes self-employment income only — if you have substantial W-2 wages, your actual Social Security portion may be lower than shown.

How accurate is this, and what does it exclude?

The arithmetic is exact for the net earnings entered, using the 2026 rates and wage base. It assumes no separate W-2 wages against the cap or the Additional Medicare threshold, and it computes self-employment tax only — not federal or state income tax, the qualified business income deduction, or estimated-tax timing. Pair it with the income-tax calculator for the full picture.