Self-Employment Tax Calculator
Everyone hears 15.3% and assumes it lands on every dollar. It does not. It applies to 92.35% of your profit, the Social Security part stops at a ceiling, and half comes back as a deduction. Your real rate is always lower.
Self-employment tax you owe
-
- Your real rate on profit
- 0%
- Taxed on (92.35% of profit)
- $0
- Social Security part
- $0
- Medicare part
- $0
- Extra Medicare, if any
- $0
- Comes back as a deduction
- $0
What the self-employment tax is made of
Each block is sized by its share, so you can see whether social Security part or medicare part is the bigger part without reading a single number.
Move it and watch
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at {v} for profit after business expenses
And what you can change
Why your own figure may differ
How the number is built
Four steps, in order. The first one is the step nobody expects.
| Step | What happens | Amount |
|---|
Taxed amount = profit x 92.35%. Social Security = the lower of that amount or what is left of the 184,500 ceiling, x 12.4%. Medicare = the whole taxed amount x 2.9%, with no ceiling. An extra 0.9% applies above the threshold for how you file.
Your real rate at different profits
It never reaches 15.3%, at any level of profit. Watch what happens once the Social Security ceiling is passed.
| Profit | Tax | Your real rate |
|---|
Self-employment tax: real examples
Three cases showing why 15.3% is not the real number. Click any card to load it.
- The usual surprise
$100,000 of profit
Self-employed full time, no other job.
The tax is $14,130. an effective 14.13%, not 15.3%. And $7,065 of it comes back as a deduction.
Load this scenario in the calculator → - A side business
$50,000 profit alongside a $150,000 job
The day job has already used most of the wage base.
Social Security only catches $34,500 of it, because the job used the rest. Most calculators miss this entirely.
Load this scenario in the calculator → - A high earner
$300,000 of profit
Past the wage base and past the extra Medicare line.
Social Security stops at the base, but Medicare keeps going and an extra 0.9% starts. The effective rate actually falls.
Load this scenario in the calculator →
Common questions about self-employment tax
Is self-employment tax really 15.3% of everything I make?
No, and this is the most common misunderstanding about it. It applies to 92.35% of your profit, not all of it. The Social Security part stops once you pass the wage base. And half of what you pay comes back as a deduction. The real bite is always below 15.3%, and the tool shows you your actual figure.
Why only 92.35% of my profit?
Someone with a job has half the payroll tax paid by their employer, and that employer half is not itself taxed. You are allowed the same treatment. Half of 15.3% is 7.65%, so 7.65% comes off first, leaving 92.35% to be taxed. It is the tax system treating you the same as an employee.
What is this tax actually for?
Social Security and Medicare. An employee pays half and their employer pays the other half. When you work for yourself you are both, so you pay both halves. That is why it feels like such a jump the first year.
Does my day job change this?
Yes, and most calculators ignore it. Wages from a job use up part of the Social Security wage base first. If your job already pays you more than the base, none of your self-employed profit is caught by the Social Security part at all. Put your wages in and watch the figure drop.
Do I pay this on top of income tax?
Yes. Self-employment tax is separate from and on top of income tax. That is why setting aside only enough for income tax leaves people badly short in April. Work out both and set aside for both.
What if I only made a little?
Below $400 of net earnings there is no self-employment tax at all. Above it, the whole amount is caught, not just the part over the line.
The guide behind this calculator
Rates and thresholds are for the 2026 tax year, read from the IRS. Social Security wage base 184,500. Checked 2026-08-18. The 92.35% figure is calculated from the published 15.3% rate, with the working recorded in the data file rather than asserted.