Gig Finance Guide
Self-Employment Tax Explained
Self-employment tax is the part of gig taxes that surprises people most — it's separate from income tax and it isn't withheld from your pay. It's also the reason a 1099 gig can owe more tax than a W-2 job at the same income. Here's exactly what it is, how it's calculated, and the breaks that soften it.
15.3% combined
12.4% Social Security + 2.9% Medicare — the employer and employee halves you now cover both of.
On 92.35% of net
SE tax applies to about 92.35% of your net self-employment profit, not your gross.
Half is deductible
You deduct half of your SE tax from income (above the line), which lowers income tax.
Social Security cap
The 12.4% Social Security portion only applies up to an annual wage base; Medicare has no cap.
What self-employment tax is
When you're an employee, you and your employer each pay half of Social Security and Medicare taxes (FICA). When you're self-employed, you're both — so you pay the whole 15.3% yourself, as self-employment (SE) tax. It funds the same Social Security and Medicare benefits.
SE tax is on top of regular federal and state income tax. That's why setting aside only enough for income tax leaves gig workers short: the 15.3% SE tax is a separate, additional bill.
How it's calculated
SE tax is figured on roughly 92.35% of your net self-employment earnings (your profit after deductions), not your gross income — so deductions like mileage lower it. The rate is 15.3%: 12.4% for Social Security plus 2.9% for Medicare.
Because it's based on net profit, every legitimate business deduction you track reduces both your income tax and your SE tax base. Confirm the current figures and the exact computation with the IRS.
The deduction for half
You get to deduct one-half of your self-employment tax as an above-the-line deduction — it lowers your taxable income (income tax) even if you don't itemize. It does not reduce the SE tax itself, but it softens the overall hit.
This is the self-employed version of the employer's half being a business cost rather than personal income, and it applies automatically when you file Schedule SE.
The Social Security cap and Additional Medicare
The 12.4% Social Security portion only applies up to an annual Social Security wage base; earnings above that aren't subject to the Social Security part (but the 2.9% Medicare part has no cap). High earners may also owe an Additional Medicare Tax above certain thresholds.
These thresholds change yearly, so check the current wage base and Additional Medicare rules on IRS.gov. This is educational information, not tax advice.
Frequently asked questions
What is self-employment tax?
It's the 15.3% tax (12.4% Social Security + 2.9% Medicare) that self-employed people pay to fund Social Security and Medicare — covering both the employer and employee halves a W-2 worker would split. It's separate from, and on top of, income tax.
How much is self-employment tax for gig workers?
The rate is 15.3%, applied to about 92.35% of your net self-employment profit (not gross). Deductions reduce the profit it's figured on, so tracking expenses like mileage lowers your SE tax. Confirm current details with the IRS.
Can I lower my self-employment tax?
You lower the base it's calculated on by claiming every legitimate business deduction (mileage, supplies, fees), which reduces net profit. Retirement contributions reduce income tax but generally not SE tax. You also deduct half of the SE tax from income.
Do I pay self-employment tax on top of income tax?
Yes. SE tax and income tax are separate. A common gig-worker mistake is setting aside only for income tax and being surprised by the additional 15.3% SE tax — which is why a 25–30% set-aside on net is a common rule of thumb.
Is there a cap on self-employment tax?
The 12.4% Social Security portion only applies up to an annual Social Security wage base; the 2.9% Medicare portion has no cap, and high earners may owe an Additional Medicare Tax. The wage base changes yearly — check the current figure with the IRS.
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This is educational information, not financial, tax, or investment advice. Rules and dollar limits change yearly — confirm current details with the IRS, HealthCare.gov, or a qualified professional for your situation.