Self-employment tax calculator

How is self-employment tax calculated?

Multiply net profit by 92.35%, then apply 15.3%: 12.4% Social Security and 2.9% Medicare. $50,000 of profit gives $46,175 of net earnings and $7,064.78 of self-employment tax.

Why 92.35%?

It takes out the equivalent of the employer half of the tax, 7.65%: 100% − 7.65% = 92.35%.

Is there a limit?

The 12.4% Social Security part applies only up to $184,500 in 2026, minus any W-2 wages you had. The 2.9% Medicare part has no limit, and above $200,000 ($250,000 joint) an extra 0.9% applies.

Can I deduct self-employment tax?

Half of it — $3,532.39 in the example — is deducted from your income for income tax, though not from the SE tax itself.

Do I owe it on small earnings?

Not if your net earnings (profit × 92.35%) are under $400. Even $400 of profit gives net earnings of $369.40 and no SE tax; the IRS test is net earnings of $400 or more.

Is self-employment tax on top of income tax?

Yes. It is a separate tax for Social Security and Medicare, computed on Schedule SE and carried to Schedule 2, so you pay it in addition to income tax. The deduction for half only lowers your income tax.

What if I also have a W-2 job?

You still owe SE tax on the business profit, and your W-2 wages use up part of the Social Security wage base. With $100,000 of W-2 wages and $100,000 of profit, only $84,500 of the $92,350 of net earnings is left under the $184,500 limit for the 12.4% part, so the SE tax is $13,156.15. Enter your wages in the second box.

Do I pay it quarterly?

The IRS says you may need to pay estimated tax each quarter, and that estimated payments can be used toward self-employment tax. The quarterly estimated tax calculator figures income tax and SE tax together.

How the tax is figured

Start with net profit: revenue minus business expenses. Net earnings are 92.35% of that. The Social Security part is 12.4% of net earnings up to the 2026 wage base of $184,500, reduced by any W-2 wages that already count toward the base. The Medicare part is 2.9% of all net earnings. The two add to the SE tax, and half of it is deducted when you figure adjusted gross income. The Additional Medicare Tax of 0.9% is not included here, and the IRS sets its thresholds by filing status.

Worked example: $50,000 and $200,000 of profit

On $50,000: net earnings $50,000 × 0.9235 = $46,175; Social Security $46,175 × 12.4% = $5,725.70; Medicare $46,175 × 2.9% = $1,339.08; total $7,064.78, with $3,532.39 deductible. On $200,000 the net earnings of $184,700 pass the wage base, so Social Security stops at $184,500 × 12.4% = $22,878; Medicare on the full amount adds $5,356.30, for $28,234.30 in all. That is 14.1% of the profit, lower than the 14.1% at $50,000.

Common mistakes

Using revenue instead of net profit is the first: the tax applies after business expenses. Forgetting the 92.35% step is the second, which overstates the tax by about 8%. Another is ignoring W-2 wages, since they use up the Social Security base. Treating the deduction for half as a reduction of SE tax is wrong too; it lowers income tax only. Last, this page covers SE tax alone; plan the quarterly payments for the total.

Sources: IRS, Topic no. 554, Self-employment tax (reviewed September 24, 2026) and Self-employment tax (Social Security and Medicare taxes) (reviewed June 27, 2026): the 15.3% rate, the $400 threshold, the deduction for half, the Additional Medicare Tax thresholds and estimated payments; IRS Publication 15 (2026) for the 2026 Social Security wage base of $184,500. The Schedule SE form and instructions give the 92.35% step. See the quarterly estimated tax calculator, the income tax calculator and the paycheck calculator for the employee side.

An estimate for planning only — not tax advice. Credits, other taxes and special cases are not included; your tax return decides. How we check our calculators.