Self-Employment Tax

Self-Employment Tax: The 15.3% Every Freelancer Pays (and How It's Really Calculated)

By Orion Luke · October 14, 2026 · 11 min read

Ask a new freelancer what tax rate they pay and you'll often hear "whatever my bracket is." That's only half the story. Before income tax even enters the picture, every self-employed person owes self-employment tax: 15.3% that funds Social Security and Medicare. Employees pay half of it without noticing — their employer pays the other half. When you're self-employed, you're both, so you pay both halves.

This guide breaks down exactly how the 15.3% is calculated, the 92.35% factor most people have never heard of, the wage base cap, the additional Medicare tax for high earners, and the deduction that softens the blow — with worked examples using 2026 figures.

What the 15.3% actually is

Self-employment tax has two pieces, mirroring what employees and employers split on a W-2 paycheck:

• Social Security: 12.4% — funds retirement, disability, and survivor benefits.
• Medicare: 2.9% — funds hospital insurance.

12.4 + 2.9 = 15.3%. An employee sees 7.65% withheld from their paycheck (6.2% Social Security + 1.45% Medicare) while their employer quietly pays the matching 7.65%. A self-employed person pays the full 15.3% themselves.

Two things people get wrong immediately: first, this is on top of federal (and state) income tax — it's a separate tax with its own calculation. Second, it applies to net earnings (profit after business expenses), not gross receipts. Every legitimate business deduction lowers your self-employment tax as well as your income tax.

The 92.35% factor

Here's the part that confuses everyone: you don't multiply 15.3% by your full net profit. You multiply it by 92.35% of your net profit.

Why? When an employee earns $100, the employer pays $7.65 in payroll tax on top of the $100 wage — the employee is only "taxed" on the $100 they received. A self-employed person is both employer and employee, so the tax code gives a rough adjustment: it lets you exclude the "employer half" (7.65%) from the base before applying the tax. 100% − 7.65% = 92.35%.

So the formula is:

Self-employment tax = net profit × 0.9235 × 0.153

This is computed on Schedule SE, which you file with your annual return. But you need the number quarterly, because it's part of every estimated payment.

The Social Security wage base ($184,500 for 2026)

The 12.4% Social Security piece doesn't apply forever. Each year the government sets a wage base — the maximum earnings subject to Social Security tax. For 2026 it's $184,500. Earnings above that are exempt from the 12.4% (though Medicare continues).

Practical notes:

• The wage base counts combined earnings: W-2 wages plus self-employment income. If you earned $100,000 at a day job and $120,000 freelancing, your total is $220,000 — Social Security tax applies to the first $184,500 across both.
• If your W-2 wages already exceed the wage base, your self-employment income owes no Social Security tax at all that year — only Medicare.

The additional Medicare tax (0.9%)

On top of everything, there's an additional 0.9% Medicare tax on earnings above $200,000 for single filers ($250,000 for married filing jointly). Unlike regular SE tax, there's no 92.35% factor here and no employer half — it's a straight 0.9% on the excess.

Note the thresholds are not indexed the same way as the wage base and haven't moved in years, so more people cross them over time.

The deduction that softens the blow

You get to deduct one-half of your self-employment tax from your income when calculating federal income tax. It's an "above-the-line" deduction — you don't need to itemize, and everyone with SE income gets it. It doesn't reduce the SE tax itself, but it shrinks the income tax computed on top of it.

Worked example 1: $60,000 net profit (single filer)

Step 1 — SE taxable earnings: $60,000 × 0.9235 = $55,410.00

Step 2 — Social Security piece: $55,410 × 0.124 = $6,870.84 (well under the $184,500 wage base, so the full amount counts)

Step 3 — Medicare piece: $55,410 × 0.029 = $1,606.89

Step 4 — Total SE tax: $6,870.84 + $1,606.89 = $8,477.73

Step 5 — Half-SE deduction: $8,477.73 ÷ 2 = $4,238.87 (deducted from income for federal income tax purposes)

Step 6 — Federal taxable income (single, standard deduction $16,100 for 2026): $60,000 − $4,238.87 − $16,100 = $39,661.13, taxed at 2026 marginal rates. (Check the current IRS tax tables for the bracket math — rates and thresholds are set annually.)

So on $60,000 of freelance profit, the SE tax alone is $8,477.73 — an effective SE rate of about 14.1% of net profit (slightly under 15.3% thanks to the 92.35% factor).

Worked example 2: $250,000 net profit (single filer, high earner)

Step 1 — SE taxable earnings: $250,000 × 0.9235 = $230,875.00

Step 2 — Social Security piece: capped at the wage base. $184,500 × 0.124 = $22,878.00

Step 3 — Medicare piece: no cap. $230,875 × 0.029 = $6,695.38

Step 4 — Additional Medicare tax: 0.9% on the amount over $200,000. $230,875 − $200,000 = $30,875. $30,875 × 0.009 = $277.88

Step 5 — Total SE tax: $22,878.00 + $6,695.38 + $277.88 = $29,851.26

Step 6 — Half-SE deduction: $29,851.26 ÷ 2 = $14,925.63

Notice how the wage base changes the picture: the effective SE rate here is about 11.9% of net profit, not 15.3%, because the 12.4% Social Security piece stopped at $184,500.

Self-employment tax and your future Social Security benefits

Paying SE tax isn't just a cost — it's buying into the system. Your self-employment earnings are credited to your Social Security earnings record, and you earn up to four "credits" per year based on covered earnings (the credit threshold is set annually — check the current SSA figures). Forty credits (roughly ten years of work) generally qualifies you for retirement benefits, and your benefit amount is based on your 35 highest-earning years. Freelancers who underreport income to dodge SE tax are also shrinking their future benefit — a tradeoff worth understanding before you get creative.

Mixed income: W-2 wages plus freelancing

This is where the wage base gets tricky, and where real money is often overpaid. Social Security tax applies to combined earnings — W-2 wages plus net self-employment earnings — up to the $184,500 wage base (2026).

Worked example: Jordan earns $130,000 in W-2 wages and $80,000 in freelance net profit.

• Combined earnings: $130,000 + $80,000 = $210,000
• Social Security applies to the first $184,500 only
• W-2 Social Security tax was already withheld on the full $130,000 (6.2% employee share)
• Remaining wage base for SE purposes: $184,500 − $130,000 = $54,500
• SE taxable earnings: $80,000 × 0.9235 = $73,880
• Social Security piece of SE tax: 12.4% × min($73,880, $54,500) = 12.4% × $54,500 = $6,758
• Medicare piece: 2.9% × $73,880 = $2,142.52 (no cap)
• Total SE tax: $8,900.52 — instead of the $11,301 you'd get ignoring the wage base

If your W-2 wages alone exceed $184,500, your freelance income owes zero Social Security tax — only the 2.9% Medicare piece (plus the 0.9% additional tax if applicable). Tax software handles this automatically via Schedule SE, but if you calculate quarterly payments by hand or in a spreadsheet, you must track year-to-date W-2 wages yourself.

The $400 threshold

You only owe self-employment tax if your net earnings from self-employment are $400 or more for the year. Below $400, no SE tax — though the income is still subject to income tax. This is a filing threshold, not a planning strategy: $399 of profit doesn't make the income tax-free.

SE tax vs. income tax, side by side

It helps to see the two taxes as separate systems that happen to be calculated on the same return:

Your quarterly estimated payment is the sum of both, which is why freelancers' effective rates surprise them: a 22% income-tax bracket plus ~14% SE tax means keeping only about 64 cents of each marginal freelance dollar before state tax.

Common mistakes

Mistake 1: Forgetting SE tax exists. New freelancers budget for "income tax" and get blindsided by an extra 15.3% layer. Your real marginal rate on freelance income is your income-tax bracket plus ~14–15% SE tax.

Mistake 2: Calculating on gross instead of net. Business expenses reduce SE-taxable earnings dollar for dollar. A $5,000 legitimate deduction saves about $765 in SE tax alone (plus income tax savings).

Mistake 3: Ignoring the wage base with mixed income. If you have both W-2 wages and freelance income, add them together before applying the $184,500 cap. Overpaying Social Security tax is a common and entirely avoidable error — the excess is credited back at filing, but that's an interest-free loan to the government.

Mistake 4: Forgetting the half-SE deduction. It's automatic, but only if you actually claim it on Schedule SE. Tax software does this for you; spreadsheet users need a line for it.

Mistake 5: Treating SE tax as optional in year one. First-year freelancers sometimes assume estimated tax starts "next year." It doesn't — the obligation starts with the first profitable quarter.

Putting it together quarterly

Every quarterly estimated payment has an SE-tax component computed exactly like the examples above, just on that quarter's net profit instead of the full year. Re-run it each quarter on actual numbers — income fluctuates, expenses fluctuate, and the wage base math only works if you're tracking year-to-date totals.

General information only — not tax advice. 2026 figures shown; verify against current IRS guidance and consult a tax professional for your situation.