Nothing rattles a first-year freelancer quite like discovering self-employment tax exists on top of ordinary income tax. It is not a penalty and it is not optional — it is simply the self-employed version of the Social Security and Medicare taxes every W-2 employee also pays, just paid entirely by you instead of split with an employer.
Where the 15.3% comes from
| Component | Rate | Applies to |
|---|---|---|
| Social Security portion | 12.4% | Net earnings up to the annual Social Security wage base |
| Medicare portion | 2.9% | All net self-employment earnings, no cap |
| Total | 15.3% | Combined rate |
An employee pays half of these rates (7.65%) through payroll withholding, and their employer quietly matches the other half. As a self-employed person, both halves land on you.
It's calculated on net earnings, not gross revenue
This is the detail that softens the blow: self-employment tax is calculated on your net profit after business expenses — not your total invoiced income. Every legitimate deduction you claim, from mileage to software subscriptions to your home office, reduces the base this tax is calculated on, not just your income tax.
The above-the-line deduction that offsets it
Here is the part many new freelancers miss entirely: you get to deduct half of your self-employment tax from your income for income-tax purposes, even if you don't itemize. It is an automatic above-the-line adjustment, not something you have to fight for.
How this connects to quarterly payments
Because no employer withholds this tax from a 1099 payment, you are expected to estimate and pay both income tax and self-employment tax four times a year. Underpay, and the IRS can charge a penalty even if you pay everything in full by the April deadline. Our guide to quarterly estimated taxes shows a simple way to set aside the right amount from every payment you receive.
A quick way to estimate what to set aside
A commonly used rule of thumb among freelancers is to reserve roughly 25–30% of net profit for combined income tax and self-employment tax, then adjust once you have a full year of actual numbers. It is not a substitute for a real calculation, but it prevents the painful surprise of an empty account in April.
Frequently asked questions
Do I owe self-employment tax if my freelance income is small?
Generally, self-employment tax applies once net self-employment earnings reach a small statutory minimum (typically $400), regardless of whether you also have a W-2 job.
Is self-employment tax the same as income tax?
No — they are calculated and reported separately. Self-employment tax funds Social Security and Medicare; income tax is calculated on your total taxable income across all sources at ordinary rates.
Does forming an LLC reduce self-employment tax?
A single-member LLC taxed as a sole proprietorship does not, by itself, change self-employment tax treatment. Some business owners explore S-Corp election for potential savings, which is a more advanced strategy worth discussing with a CPA.