If you’ve looked at your first freelance tax bill and thought «wait, this is more than I expected,» self-employment tax is probably why. It’s the single biggest tax surprise for new freelancers — a tax that traditional employees never see broken out separately, because their employer quietly covers half of it. This guide breaks down exactly what self-employment tax is, how it’s calculated, and how it fits together with your regular income tax.
Disclaimer: This article is for general educational purposes only and is not personalized tax advice. Rates and thresholds are adjusted periodically. Confirm current-year figures on IRS.gov or with a licensed tax professional before filing.
What Is Self-Employment Tax?
Self-employment tax is how freelancers, independent contractors, and small business owners pay into Social Security and Medicare — the same programs that W-2 employees fund through payroll withholding.
The key difference: when you work for an employer, the cost is split. Your employer pays half, and half comes out of your paycheck. When you’re self-employed, you are effectively both the employer and the employee, so you’re responsible for the entire amount yourself.
This is separate from — and in addition to — your regular federal income tax.
The Self-Employment Tax Rate
Self-employment tax is 15.3% of your net self-employment earnings, made up of two parts:
- 12.4% for Social Security
- 2.9% for Medicare
The Social Security Portion Has a Cap
The 12.4% Social Security portion only applies up to a certain amount of net earnings each year (the «wage base limit,» which is adjusted annually for inflation). Earnings above that threshold are not subject to the Social Security portion, though they remain subject to the Medicare portion.
The Medicare Portion Has No Cap — Plus an Additional Surtax
The 2.9% Medicare portion applies to all of your net self-employment earnings, with no upper limit. High earners also pay an additional 0.9% Medicare surtax on earnings above a certain threshold (which depends on filing status), on top of the standard 2.9%.
How Self-Employment Tax Is Calculated (Step by Step)
Step 1: Calculate Your Net Earnings From Self-Employment
Start with your total freelance/business income, then subtract your business expenses and deductions. This is your net profit, typically calculated on Schedule C of your tax return.
Step 2: Apply the 92.35% Rule
The IRS lets you calculate self-employment tax on 92.35% of your net earnings, not the full 100%. This accounts for the fact that a traditional employee’s share of payroll tax is calculated on their gross wage, not on a wage that’s already been reduced by the employer’s matching contribution — the 92.35% adjustment roughly equalizes the comparison.
Taxable SE earnings = Net profit × 0.9235
Step 3: Apply the 15.3% Rate
Self-employment tax = Taxable SE earnings × 15.3% (up to the Social Security wage base; earnings above that are taxed at 2.9% for Medicare only)
Example: Freelance Photographer With $60,000 Net Profit
- Net profit: $60,000
- Taxable SE earnings: $60,000 × 0.9235 = $55,410
- Self-employment tax: $55,410 × 15.3% = $8,477.73
That’s roughly $8,478 owed in self-employment tax alone — before any regular federal or state income tax is even calculated on top of it. This is exactly why the «25–30% of every payment» savings guideline from our tax savings guide feels high to new freelancers at first, but reflects the real combined burden.
The Good News: You Get to Deduct Half of It
Here’s a detail that surprises a lot of freelancers in a good way: you can deduct half of your self-employment tax from your taxable income when calculating your regular income tax. This mirrors the fact that a traditional employer’s half of payroll tax is a business expense for them, not taxable income for the employee — the deduction puts self-employed workers on more equal footing.
Using the example above, this freelancer could deduct roughly $4,239 (half of $8,477.73) from their income before calculating federal income tax — a meaningful reduction in their overall taxable income.
Self-Employment Tax vs. Income Tax: What’s the Difference?
This distinction trips up a lot of new freelancers, so it’s worth spelling out clearly:
| Self-Employment Tax | Federal Income Tax | |
|---|---|---|
| What it funds | Social Security & Medicare | General government spending |
| Rate | Flat 15.3% (with caps/surtax as noted) | Graduated brackets based on income |
| Applies to | Net self-employment earnings | All taxable income (freelance + other sources) |
| Can be reduced by business deductions? | Yes | Yes |
Both taxes apply at the same time, on top of each other — which is why your total tax burden as a freelancer often feels significantly higher than it did as a W-2 employee, even at a similar income level.
Does Self-Employment Tax Apply to Everyone Who Freelances?
Generally, if your net self-employment earnings are $400 or more in a year, you’re required to pay self-employment tax, regardless of whether you also have a regular job. This threshold is intentionally low — even relatively small side-hustle income can trigger the requirement.
How This Fits Into Your Bigger Tax Picture
Self-employment tax is just one piece of what you owe. To put it all together:
- Calculate your net profit (income minus business deductions).
- Calculate self-employment tax (as shown above).
- Calculate your federal income tax on your taxable income (which includes the deduction for half of your SE tax).
- Add any state income tax owed.
- Pay the total across the year through quarterly estimated payments (see our complete guide to quarterly estimated taxes for freelancers).
Frequently Asked Questions
Is self-employment tax the same as income tax? No. Self-employment tax specifically funds Social Security and Medicare, while income tax funds general government spending. Freelancers pay both.
Can business deductions reduce my self-employment tax? Yes — self-employment tax is calculated on your net profit after business deductions, so legitimate write-offs (see our guide to the top tax deductions for freelancers) reduce both your income tax and your self-employment tax.
Do I pay self-employment tax if I also have a W-2 job? Yes, on your freelance/self-employment earnings specifically. However, if your W-2 wages already exceed the Social Security wage base limit for the year, you may not owe the Social Security portion again on your self-employment income — this is a detail worth reviewing with a tax professional if it applies to you.
Does forming an LLC reduce self-employment tax? A standard single-member LLC is generally taxed the same as a sole proprietorship for self-employment tax purposes. Some freelancers explore electing S-corp tax treatment once their income grows significantly, as it can potentially reduce self-employment tax exposure — but this involves added complexity and costs, and is worth a dedicated conversation with a CPA rather than a DIY decision.
Key Takeaway
Self-employment tax — 15.3% of your net earnings, covering Social Security and Medicare — is often the biggest tax surprise for new freelancers, but understanding how it’s calculated makes it far less intimidating. Combined with regular income tax, it’s the reason freelancers need to set aside a meaningful percentage of every payment (see our guide on how much to save for taxes), and why tracking your legitimate business deductions carefully has a bigger impact on your bottom line than most new freelancers realize.