Self-Employment Tax Calculator
Estimate self-employment tax on your net profit with editable Social Security and Medicare rates, wage base, surtax threshold and the deductible half.
Rates, caps and thresholds — every one is editable
How the tax is built
| Component | Amount taxed | Rate | Tax |
|---|---|---|---|
| Net earnings (92.35% of profit) | $85,000.00 | 92.35% | $78,497.50 |
| Social Security | $78,497.50 | 12.4% | $9,733.69 |
| Medicare | $78,497.50 | 2.9% | $2,276.43 |
| Additional Medicare surtax | $0.00 | 0.9% | $0.00 |
| Total | — | 15.30% | $12,010.12 |
Net earnings from self-employment = net profit × 92.35%. Social Security applies to those earnings up to the wage base, reduced by any W-2 wages that already used part of it; Medicare applies to all of them; the additional Medicare surtax applies above the threshold for your filing status. Half of the Social Security and Medicare total is deductible against income tax. Every rate, cap and threshold above is an editable field with a labelled default rather than a hardcoded universal, because they change each year. This is an estimate for planning, not tax advice — check the current figures with the IRS or a tax professional.
What is the Self-Employment Tax Calculator?
The ByteTools Self-Employment Tax Calculator turns your Schedule C net profit into the Social Security and Medicare tax a sole trader or freelancer owes.
- Net earnings from self-employment at the standard 92.35% factor, editable
- Social Security capped at the wage base and reduced by W-2 wages already taxed
- Additional Medicare surtax with per-filing-status thresholds
- Deductible one-half of self-employment tax calculated for you
- Component build-up table showing the amount taxed at each rate
- Every rate, cap and threshold is an input with a labelled default, never a hardcoded universal
How to use the Self-Employment Tax Calculator
- 1
Enter your net profit from self-employment and any W-2 wages already subject to Social Security.
- 2
Check the rates panel — the net earnings multiplier, Social Security rate and wage base, Medicare rate and surtax rate all default to the current federal figures and can be edited.
- 3
Pick your filing status to set the additional Medicare threshold, or enter your own.
- 4
Read the total self-employment tax, the deductible one-half and your effective rate on profit.
- 5
Use the build-up table to see exactly which amount each rate was applied to.
About the Self-Employment Tax Calculator
The ByteTools Self-Employment Tax Calculator turns your Schedule C net profit into the Social Security and Medicare tax a sole trader or freelancer owes. It multiplies profit by the net earnings factor, applies Social Security up to the wage base, Medicare with no cap and the additional Medicare surtax above your filing threshold, then shows the deductible half.
Every rate, cap and threshold is an editable field with a labelled default rather than a hardcoded constant, because they change every year and no calculator can promise a current table. If you also have W-2 wages, entering them reduces the Social Security wage base left for your self-employment income so you are not double-charged.
All arithmetic happens locally in your browser and nothing about your income is uploaded or saved. These figures are a planning estimate, not tax advice — check the current rates with the IRS or a tax professional before filing.
Frequently asked questions
How much is self-employment tax?
The combined rate is 15.3% — 12.4% for Social Security up to the annual wage base and 2.9% for Medicare with no cap — but it applies to 92.35% of your net profit rather than all of it. On 100,000 of profit that works out to 14,129.55.
Why is self-employment tax based on 92.35% of profit?
An employee's share of payroll tax is not counted as part of their wages, so the law levels the field by removing the employer-equivalent 7.65% from your profit before applying the rates. Multiplying by 92.35% is exactly that adjustment.
Can I deduct self-employment tax?
You can deduct half of the Social Security and Medicare portion against your income tax, which is the employer-equivalent share. The calculator shows that figure separately. The additional Medicare surtax is not part of the deductible half.
Do I owe self-employment tax if I also have a job?
Yes on your self-employment profit, but your W-2 wages use up part of the Social Security wage base first. Enter those wages here and the calculator reduces the base remaining for your self-employment income, so the Social Security component is not charged twice.
Is there a minimum before self-employment tax applies?
Net earnings below a small floor — 400 by default in this tool — do not attract self-employment tax at all. The calculator shows a clear message rather than a tax figure when your earnings fall under the threshold you have set.
Are these rates guaranteed to be current?
No, and that is why every one of them is an editable field. Rates, the wage base and the surtax thresholds change from year to year, so check the current figures with the IRS and update the inputs before relying on the result.
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