Self-employment tax calculator for 2026
If you work for yourself, you pay both halves of Social Security and Medicare — 15.3% on most of your profit, on top of income tax. Here's what yours comes to, what to set aside each quarter, and whether an S corporation would cut it.
How self-employment tax is worked out
- Start from 92.35% of your net profit. That's your net earnings from self-employment — the 7.65% taken off stands in for the employer's half an employee never sees. If it's under $400, there's no self-employment tax.
- Social Security: 12.4% of those earnings, up to $184,500 in 2026. W-2 wages from a job use up that limit first, so if you also have a salary, less of your self-employment income is taxed for Social Security.
- Medicare: 2.9% of all of it, with no limit.
- Additional Medicare: 0.9% on earnings above $200,000, or $250,000 on a joint return. Wages count toward that threshold first — on a joint return, both spouses' wages.
Half of the Social Security and Medicare parts is deductible when you work out your income tax, which lowers your income tax a little. It doesn't lower the self-employment tax itself.
Quarterly payments
No one withholds self-employment tax for you, so it's paid through estimated tax along with your income tax. For2026 the payments are due April 15, 2026, June 15, 2026, September 15, 2026 and January 15, 2027. The calculator's quarterly figure is the self-employment tax alone — set aside your income tax on top of it.
Ways to lower it
- Claim every legitimate business expense. Self-employment tax is on profit, so each deductible cost lowers it by about 14%, and your income tax too.
- Consider an S corporation once profit is well above what you'd pay yourself. You'd pay payroll tax on a reasonable salary instead of self-employment tax on all the profit — but also payroll, a second return, and for many owners a smaller QBI deduction. The S corp calculator weighs all of it and tells you when it doesn't pay.
What doesn't lower it: contributing to a retirement plan or paying health insurance. Those reduce income tax, not self-employment tax. Whether any of this fits your situation is a question for your CPA or tax attorney.
Sources
- IRC §1401 — the 12.4% and 2.9% rates, and the additional 0.9%
- IRC §1402 — net earnings, the 92.35% rule, the $400 minimum, and wages against the wage base
- SSA contribution and benefit base — $184,500 for 2026
- Form 8959 instructions — the additional Medicare tax with both wages and self-employment income
- IRC §164(f) — deducting half of self-employment tax
- IRC §162(l)(4) — the health insurance deduction doesn't reduce self-employment earnings
- Form 1040-ES — estimated tax and its 2026 due dates
General information, not advice for your situation. Whether a strategy fits depends on your facts — talk to your CPA or tax attorney about whether you qualify before you put it in place. Your accountant remains responsible for your return.
Know where yours stands, all year.
OpenYear reads your books, shows which strategies fit your business and why, and keeps the records each one needs — ready for your accountant. It's built for owner-operated S corporations.