Self-Employment Tax Calculator

Fact-checked by the LegalGlass editorial team against primary sources · Published Aug 6, 2026 · Last updated Aug 6, 2026

Self-employment tax is 15.3% of 92.35% of your net self-employment earnings: 12.4% for Social Security (up to the annual wage base) plus 2.9% for Medicare (no cap). The calculator below estimates what you owe and the deductible half.

Quick Answer

SE tax rate: 15.3% (12.4% Social Security + 2.9% Medicare)
Taxable base: 92.35% of net self-employment earnings
Social Security cap: Applies only up to the annual wage base (editable below)
Additional Medicare: +0.9% over $200k single / $250k married filing jointly
Deduction: Half of SE tax is deductible for income tax
Minimum: No SE tax if net earnings are under $400

Net self-employment earnings ($)

Filing status

Social Security wage base ($) - 2025 figure $176,100; confirm current year at SSA

Net earnings × 92.35%	$73,880.00
Social Security (12.4%)	$9,161.12
Medicare (2.9%)	$2,142.52
Additional Medicare (0.9%)	$0.00
Estimated self-employment tax	$11,303.64
Deductible half (income-tax adjustment)	$5,651.82

Estimate only. Figures round to the nearest cent. Confirm current-year thresholds with the IRS and SSA; see sources below.

How Self-Employment Tax Is Calculated

Self-employment (SECA) tax funds Social Security and Medicare for people who work for themselves - the equivalent of the payroll taxes an employer and employee split, both halves paid by you. The calculation has four steps:

Start with net earnings. That is your business profit - for most filers, the net profit on Schedule C.
Multiply by 92.35%. This removes the employer-equivalent share, so you are not taxed on the portion you later deduct.
Apply 12.4% Social Security to that base, but only up to the annual Social Security wage base. Earnings above the base owe no Social Security portion.
Apply 2.9% Medicare to the entire base (no cap), plus the 0.9% Additional Medicare Tax on amounts above $200,000 (single) or $250,000 (married filing jointly).

The Formula

In plain terms: SE tax = (net earnings × 0.9235 × 12.4%, capped at the wage base) + (net earnings × 0.9235 × 2.9%) + additional Medicare where it applies. You then deduct one-half of the result as an adjustment to income on Form 1040.

Rates and Thresholds

Component	Rate	Applies to
Social Security (OASDI)	12.4%	92.35% of net earnings, up to the wage base
Medicare (HI)	2.9%	92.35% of net earnings, no cap
Additional Medicare	0.9%	Earnings over $200k single / $250k MFJ
Combined base rate	15.3%	Below the wage base

Worked Example

Take a freelancer with $80,000 of net profit on Schedule C, filing single, in a year when the Social Security wage base is $176,100. First, multiply $80,000 by 92.35% to get a taxable base of $73,880. Because $73,880 is below the wage base, the full amount is subject to the 12.4% Social Security portion: $73,880 × 12.4% = $9,161.12. The 2.9% Medicare portion applies to the same base: $73,880 × 2.9% = $2,142.52. The base is under $200,000, so no Additional Medicare Tax applies. Total self-employment tax is $9,161.12 + $2,142.52 = $11,303.64. The filer then deducts half of that - $5,651.82 - as an adjustment to income, which lowers taxable income (not the SE tax). That is exactly what the calculator above shows for these inputs; change any field and it recomputes.

Now suppose net profit were $250,000 instead. The 12.4% Social Security portion would stop at the wage base, so it applies to $176,100 rather than the full 92.35% base - capping the Social Security piece. Medicare still applies to the entire 92.35% base with no cap, and the 0.9% Additional Medicare Tax kicks in on the portion above the $200,000 threshold. This is why high earners see their marginal SE tax rate drop from 15.3% toward 2.9% (plus 0.9%) once past the wage base - a key reason an S-corp election is weighed at higher profit levels.

Common Mistakes

Applying 15.3% to the full profit instead of to 92.35% of it - that overstates the tax.
Forgetting the Social Security wage-base cap, which lowers the tax for higher earners.
Ignoring W-2 wages from another job, which count toward the same wage base.
Confusing the deductible half (an income-tax adjustment) with a reduction of the SE tax.
Skipping quarterly estimated payments and owing an underpayment penalty at filing.

Who Owes Self-Employment Tax

You owe SE tax if you had $400 or more of net self-employment earnings: sole proprietors, single-member LLC owners, partners in a partnership, and most independent contractors and gig workers. Wages already subject to Social Security tax count toward the wage base, which can reduce the Social Security portion of your SE tax if you also have a W-2 job.

How an S-Corp Election Changes This

Electing S-corp status can change the math: an S-corp owner pays payroll tax only on a reasonable salary, and remaining profit distributions are not subject to SE tax. Whether that saves money depends on your profit, a reasonable salary for your role, and added payroll and filing costs. See S corp vs LLC and how LLC and S-corp taxes differ.

How You Pay and Report It

You calculate self-employment tax on Schedule SE and report it with your Schedule C on Form 1040. Because there is no employer withholding, most self-employed people pay as they go through quarterly estimated tax payments; underpaying during the year can trigger a penalty even if you pay in full at filing. Keep records of income and expenses so your net earnings - the figure this calculator starts from - are accurate. If you also draw a W-2 salary, coordinate the wage base across both so you do not overpay the Social Security portion.

Frequently Asked Questions

What is the self-employment tax rate?

15.3% (12.4% Social Security + 2.9% Medicare) on 92.35% of net earnings. Social Security stops at the wage base; Medicare has no cap.

Why is only 92.35% of my income taxed?

Multiplying by 92.35% removes the employer-equivalent share, so you are not taxed on the portion you later deduct.

Can I deduct self-employment tax?

Yes - one-half of it, as an adjustment to income on Form 1040. It reduces income tax, not the SE tax itself.

What is the Additional Medicare Tax?

An extra 0.9% on earnings above $200,000 (single) or $250,000 (married filing jointly).

Do I owe SE tax if my business lost money?

No. SE tax applies only to net profit; under $400 in net earnings generally owes none.

Sources

IRS - Self-Employment Tax (Social Security and Medicare Taxes).
IRS - Topic No. 554, Self-Employment Tax.
IRS - About Schedule SE (Form 1040).
IRS - Additional Medicare Tax.
SSA - Contribution and Benefit Base (Social Security wage base by year).
Cornell LII - 26 U.S. Code § 1401, Rate of tax.

This calculator provides a general estimate for educational purposes and is not tax advice. LegalGlass is not a law firm or accounting firm. Verify current-year rates and thresholds with the IRS and SSA and consult a qualified tax professional for your situation.