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Self-Employment Tax Calculator

Calculate SE tax, Social Security, and Medicare contributions for freelancers and independent contractors.

Tested tool guide Tested browser tools Checked August 16, 2026

What Self-Employment Tax Calculator does, with a checked example

Self-employment tax is the Social Security and Medicare tax freelancers pay instead of the payroll withholdings that come out of an employee's paycheck. This calculator takes your net profit and returns the SE tax for the tax year you select, split into its Social Security and Medicare parts, plus the deduction for half the tax that lowers your income tax. Everything is computed in your browser; the figures never leave your machine. The first number most people enter wrong is gross revenue: the tax applies to profit after business expenses. And the 15.3% headline is not the effective rate - the IRS charges it on only 92.35% of net earnings.

Worked example

A concrete input and expected output from the current implementation.

Input

Net profit: $50,000 | Tax year: 2025 | Filing status: Single | W-2 wages: $0

Expected output

Self-employment tax: $7,064.78. Social Security: $5,725.70 (12.4% of $46,175). Medicare: $1,339.08 (2.9% of $46,175). Deductible half of SE tax: $3,532.39.

Net earnings from self-employment are 92.35% of net profit: $50,000 x 0.9235 = $46,175. Since that is below the 2025 wage base of $176,100 and below the $200,000 additional-Medicare threshold, the tax is simply 15.3% of $46,175, which rounds to $7,064.78.

How the result is produced

1

From profit to taxable base

The tool first converts net profit into net earnings from self-employment by multiplying by 92.35%. That factor strips out the employer-equivalent half of the combined rate, which the IRS treats as a deductible business expense. The result is the base on which both parts of the tax are charged, and it is the same figure Schedule SE carries onto your return when you file.

2

Rate split, caps, and the deduction

Social Security is 12.4% of that base up to the year's wage base, which changes annually; Medicare is 2.9% with no cap, and an additional 0.9% applies above $200,000 for single filers or $250,000 for married filing jointly. The calculator also reports half of the total SE tax, which you deduct from gross income when computing income tax on the same return.

Good uses

  • Planning quarterly estimated payments: the SE tax lands on Form 1040-ES alongside income tax, and underpaying it can trigger penalties.
  • Comparing a W-2 job offer with a 1099 contract at the same gross pay, since you carry both halves of Social Security and Medicare when self-employed.
  • A side gig on top of a salary: when W-2 wages already pass the Social Security wage base, the extra 1099 income may face only the Medicare part, changing how much to set aside.

Limits and checks

  • Enter net profit after expenses, not gross revenue, and understand the result covers only SE tax. Federal income tax, state tax, and the Qualified Business Income deduction are computed separately, so the number understates your total tax bill.
  • Every threshold is year- and status-specific. The Social Security wage base rises most years, and additional Medicare depends on filing status and on combined W-2 plus self-employment earnings, not on this income alone.
  • The 15.3% rate is charged on 92.35% of profit, which is about 14.13% in practice, and the half-tax deduction trims income tax on top. For a year with net earnings under $400, no SE tax is owed at all.

Common questions

Do I still owe income tax on top of this?

Yes. Self-employment tax covers only Social Security and Medicare. Your federal income tax on the same profit, plus state tax where applicable, is separate and generally larger for most freelancers. That is why the SE-tax figure alone understates what to set aside, and why estimated payments combine both pieces.

I have a W-2 job and freelance on the side. Do I pay 15.3% on everything?

Not on everything. The 12.4% Social Security portion stops once your combined wages and self-employment earnings pass the year's wage base; above that you pay only the 2.9% Medicare portion, plus 0.9% additional Medicare if the threshold applies. Below $400 of net earnings for the year, no SE tax is due. Enter your W-2 wages and filing status where the calculator asks for them, or its Social Security figure will be overstated.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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