Self-Employment Tax Calculator
Estimate self-employment tax and quarterly payments.
Schedule C net earnings before the self-employment tax deduction.
Self-employment tax
- Net earnings subject to SE tax
- $83,115.00
- Total tax owed
- $12,716.60
- Deductible half of SE tax (above-the-line)
- $6,358.30
- Estimated quarterly payment
- $3,179.15
2026 US federal figures per IRS Rev. Proc. 2025-32; results are a simplified estimate. SE tax is Social Security plus regular Medicare; the 0.9% Additional Medicare tax is shown separately and is not deductible. Quarterly is a simple total / 4 and does not apply the IRS safe-harbor rule. Not tax advice. Your figures stay on this device and are never put in the URL.
How the self-employment tax calculator works
Self-employment tax is the Social Security and Medicare tax that freelancers and sole proprietors pay on their own profit. An employee splits this tax with an employer; a self-employed person pays both halves. This calculator takes your net profit (Schedule C net earnings) and the year’s Social Security wage base, then computes the tax, the deductible half, and a rough quarterly payment.
The method follows IRS line-by-line rounding. First it shrinks profit to the taxable base: seBase = netProfit * 0.9235. Then it applies three rates: Social Security at 12.4% on the base up to the wage base cap, Medicare at 2.9% on the full base, and an Additional Medicare tax of 0.9% on any base above the threshold (default $200,000). Social Security plus regular Medicare make up the self-employment tax proper: seTax = socialSecurity + medicare. The Additional Medicare tax sits outside it (IRS Form 8959), so the deductible half is seTax / 2, while the total owed is totalTax = seTax + additionalMedicare and the quarterly estimate is totalTax / 4. If net profit is $400 or less, the tax is zero.
Worked example
Take a freelancer with $90,000 of net profit and a Social Security wage base of $168,600.
| Step | Calculation | Result |
|---|---|---|
| Taxable base | 90,000 × 0.9235 | 83,115.00 |
| Social Security | 83,115 × 0.124 | 10,306.26 |
| Medicare | 83,115 × 0.029 | 2,410.34 |
| Additional Medicare | base is below 200,000 | 0.00 |
| Self-employment tax | 10,306.26 + 2,410.34 | 12,716.60 |
| Deductible half | 12,716.60 ÷ 2 | 6,358.30 |
| Quarterly estimate | 12,716.60 ÷ 4 | 3,179.15 |
The base of $83,115 sits under the $168,600 cap, so the full base is hit by Social Security. It is also under the $200,000 Additional Medicare threshold, so that line is zero. The freelancer owes $12,716.60 in self-employment tax, can deduct $6,358.30 above the line, and would set aside roughly $3,179.15 per quarter for this tax alone.
How to use it
- Enter net profit, which is gross freelance income minus deductible business expenses, not your total revenue.
- Use the current year’s Social Security wage base; it changes annually, so check the figure for your tax year.
- Set the Additional Medicare threshold to match your filing status ($200,000 single, $250,000 married filing jointly, $125,000 married filing separately).
- Read the deductible half as an income tax adjustment, then add your income tax estimate on top of the quarterly figure to size your actual payment.
Limitations
This calculator covers only the self-employment tax, not federal or state income tax, which you will also owe on the same profit. It does not net out W-2 wages against the Social Security cap, apply the IRS safe-harbor rules, prorate for partial years, or account for state-level taxes. The quarterly figure assumes even income across four periods. It is an estimate for planning, not a filing or professional tax advice. Confirm your numbers with a qualified tax professional or current IRS forms before you pay.
Frequently asked questions
Do I owe self-employment tax if I had a regular job too?
Yes. Self-employment tax applies to your net freelance or business profit regardless of W-2 wages from a job. However, your W-2 wages count first against the Social Security wage base, so if your job already used part of the cap, less of your self-employment income is subject to the 12.4% Social Security portion. This calculator does not net out prior W-2 wages, so reduce the wage base input manually if that applies to you.
Why is only 92.35% of my profit taxed?
The 0.9235 factor removes the employer-equivalent half of the tax from the base before applying the rates. It mirrors the fact that an employee's FICA is calculated on wages after the employer's share is excluded. Multiplying net profit by 0.9235 keeps self-employed people roughly even with employees who split the tax with an employer.
Is the half-deduction the same as a business expense?
No. The deductible half of your self-employment tax is an above-the-line adjustment to income, not a Schedule C business expense. It lowers your adjusted gross income and therefore your income tax, but it does not change the self-employment tax itself or your net profit figure.
What happens if my net profit is under $400?
If net profit is $400 or less, you owe no self-employment tax and the calculator returns zero for the tax, the deduction, and the quarterly estimate. You may still owe income tax on that profit. The calculator still shows the 92.35% base figure for reference.
Does the quarterly number tell me exactly what to send the IRS?
No. The quarterly figure is the total shown by the tool (self-employment tax plus any Additional Medicare tax) divided by four. It does not include income tax, does not apply the IRS safe-harbor rules, and assumes even income across the year. Treat it as a starting point, then adjust for your income tax and any uneven earnings.