Freelance planning
Self-Employment Tax Estimator
Estimate US self-employment tax (Social Security + Medicare + Additional Medicare) from your net self-employment profit, W-2 wages already earned, and filing status. Does NOT estimate federal income tax, state tax, or deductions.
Formula
- Net earnings = max(0, Net profit * 0.9235)
- Social Security taxable = min(Net earnings, max(0, $184,500 - W-2 wages))
- Social Security tax = Social Security taxable * 12.4%
- Medicare tax = Net earnings * 2.9%
- Additional Medicare taxable = min(Net earnings, max(0, W-2 wages + Net earnings - filing status threshold))
- Additional Medicare tax = Additional Medicare taxable * 0.9%
- Regular SE tax = Social Security tax + Medicare tax
- Total SE tax = Regular SE tax + Additional Medicare tax
- Deductible half = Regular SE tax * 0.5 (Additional Medicare is NOT included)
- Quarterly set-aside = Total SE tax / 4
- Effective rate = Total SE tax / Net profit * 100
Examples
- A solo freelancer with $80,000 net profit and no W-2 wages owes about $11,303 in SE tax, with about $5,652 deductible above the line and a quarterly set-aside near $2,826.
- If the same person also has $100,000 in W-2 wages, the Social Security portion is capped because part of the $184,500 wage base is already used by W-2 wages, lowering the Social Security tax owed.
- Combined income (W-2 + SE) above $200,000 Single or $250,000 Married filing jointly triggers the 0.9% Additional Medicare Tax on the amount above the threshold.
When to use this calculator
- Estimate how much SE tax to set aside each quarter.
- See how W-2 wages from a part-time job reduce the Social Security portion of SE tax.
- Check the impact of crossing the Additional Medicare Tax threshold.
Common mistakes
- Forgetting the 92.35% net earnings adjustment and overestimating SE tax.
- Treating SE tax as the total tax bill; federal income tax and state tax are separate and usually larger.
- Including Additional Medicare Tax in the deductible half; only regular Social Security plus Medicare counts.
Frequently asked questions
What is self-employment tax?
Self-employment tax is the Social Security and Medicare tax paid by people who work for themselves. In 2026, the rate is 12.4% for Social Security up to the $184,500 wage base, plus 2.9% for Medicare on all net earnings, plus 0.9% Additional Medicare Tax on combined earnings above the filing-status threshold. It is separate from federal income tax and state tax.
Why does the calculator multiply profit by 92.35%?
The 92.35% factor represents net profit minus the employer-equivalent half of Social Security and Medicare. The IRS uses this adjustment so that the SE tax base mirrors how a W-2 employee's wages are reduced by the employer's payroll tax contribution. Net earnings = Net profit * 0.9235, and the SE tax rates are then applied to net earnings.
Does this include federal income tax?
No. This calculator estimates self-employment tax only. Federal income tax is separate, depends on filing status, deductions, credits, brackets, and other income, and is usually a larger number than SE tax. State tax is also separate. Treat this number as one piece of your total tax liability, not the full picture.
How do W-2 wages affect the estimate?
W-2 wages count against the same $184,500 Social Security wage base. If you have $100,000 in W-2 wages, only $84,500 of self-employment net earnings is subject to the 12.4% Social Security portion. W-2 wages also count toward the Additional Medicare Tax threshold based on your filing status, which can push more of your self-employment income above the threshold.
What is Additional Medicare Tax?
Additional Medicare Tax is an extra 0.9% on combined wages and self-employment income above the filing-status threshold: $200,000 for Single or Head of household, $250,000 for Married filing jointly, $125,000 for Married filing separately. It is reported on Form 8959 and is paid only by the individual; there is no employer-equivalent.
Why is half of self-employment tax deductible?
When you are self-employed, you pay both the employee and employer halves of Social Security and Medicare. The IRS lets you deduct the employer-equivalent half above the line on Schedule 1, which reduces your adjusted gross income (and therefore federal income tax). Only the regular Social Security plus Medicare portion is included in this deduction. Additional Medicare Tax is NOT included.
What if my net earnings are under $400?
Generally, you do not owe self-employment tax if your net earnings from self-employment are less than $400 for the year. The calculator returns zero SE tax in that case and shows a note. Other tax rules (income tax filing requirements, church employee income, etc.) may still apply, so check the IRS Schedule SE instructions or a tax professional.
How should I use this with the Freelance Rate Calculator?
The Freelance Rate Calculator asks for an estimated tax percentage to back into the hourly rate you need to charge. Take the Effective SE tax rate from this calculator, add your estimated federal and state income tax percentages, and use that combined figure as the tax input in the Freelance Rate Calculator. The two together give a more realistic hourly target.
Related calculators
Sources and assumptions
IRS: Self-Employment Tax (SS and Medicare)IRS Topic 554: Self-employment taxIRS Topic 751: Social Security and Medicare rates
- Uses the 2026 Social Security wage base of $184,500.
- Applies the 92.35% net earnings factor before computing Social Security and Medicare.
- Uses 12.4% Social Security, 2.9% Medicare, and 0.9% Additional Medicare Tax.
- Additional Medicare Tax thresholds: $200,000 (Single / Head of household), $250,000 (Married filing jointly), $125,000 (Married filing separately).
- Does NOT estimate federal income tax, state tax, deductions, credits, quarterly safe-harbor penalties, or the optional Schedule SE methods (farm or nonfarm).
- This is not tax advice. Always confirm with a qualified tax professional before filing or planning quarterly payments.
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This estimator covers self-employment tax only (Social Security, Medicare, Additional Medicare). It does NOT estimate federal income tax, state tax, deductions, credits, or penalties. For total tax planning, use this number as one input alongside a separate income tax estimate or a professional.