Self-employment tax calculator: what will I owe?

A 1099 doesn't come with tax taken out, so the bill arrives later and all at once, which is a hard way to find out. The calculator follows Schedule SE line by line, so you can check each figure against your own form.

We start from profit, not from what you were paid. Business expenses come off first. Then only 92.35% of the profit is taxed: the law takes off 7.65%, half the combined rate, before the rates apply. If what's left is under $400, there's no self-employment tax at all.

Next comes Social Security, at 12.4%. It reaches only the first $184,500 of your combined wages and self-employment earnings in 2026 ($176,100 in 2025). Wages from a W-2 job fill that space first. So if you also hold a job, less of your side income takes the 12.4%, and once your wages pass the line, none of it does. Medicare, at 2.9%, has no ceiling. The two together are your self-employment tax. Half of it comes off your income when you work out your income tax, which lowers that tax, not this one.

Higher earners can owe one more thing. The 0.9% Additional Medicare Tax starts above $200,000 for single filers, $250,000 on a joint return and $125,000 for married people filing separately, and your wages count toward the line first. It goes on its own form, Form 8959, so we keep it apart.

For the quarterly payments we follow Form 1040-ES. If you filed a return covering all 12 months last year, its tax gives you one safe-harbor amount: 100%, or 110% if last year's AGI was over $150,000 ($75,000 if you're married filing separately this year). Your expected withholding counts toward it. What's left is split across four dates, and any odd cent goes on the first payments. Paying each amount by its due date generally keeps the underpayment penalty away, even if this year's bill turns out bigger.

One thing we round on purpose: every line goes to the nearest cent before the next line uses it, the way the form is filled in. It changes one case only. A profit of $433.13 comes to $400.00 after the 92.35% step, so it's taxed. Worked to the last decimal, that profit falls a hair under $400, and section 1402 of the tax code doesn't tax earnings under $400. When we checked on October 8, 2026, neither that section nor the Schedule SE instructions said which reading wins. If your profit lands on that exact cent, we'd ask a tax preparer before relying on our figure.

What we leave out: federal income tax on the same profit, state and local tax, and the special cases (church employee income, ministers, the farm and nonfarm optional methods, nonresidents). If your spouse is self-employed too, work each of you out separately. We can't combine you for the 0.9%. And if you're filing jointly this year but didn't last year, or the reverse, Form 1040-ES shows how to combine or split last year's tax before you type it.

The rates, limits and dates all come from the IRS forms and the tax code listed under Sources and last checked. We haven't estimated any of them.