A self employment tax calculator estimates the Social Security and Medicare tax you owe on net business profit for tax year 2026, before income tax. Formula: SE base = profit × 92.35%; SE tax = 12.4% × min(base, $184,500) + 2.9% × base; deduction = half of SE tax. On $80,000 of net profit, the 2026 self-employment tax is about $11,304: 15.3% of the $73,880 taxable base.
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How to use the self employment tax calculator
- Enter net self-employment profit: income minus business expenses from Schedule C, or your share from a partnership.
- Enter your marginal federal income tax rate.
- Read the taxable base, the Social Security and Medicare parts, income tax at your rate and a quarterly set-aside.
What formula does the self employment tax calculator use?
- Taxable base = net profit × 92.35%.
- Social Security = 12.4% of the base, up to the 2026 wage base of $184,500.
- Medicare = 2.9% of the full base, with no limit.
- Half of the self-employment tax is deducted when figuring income tax.
- No tax is due if net earnings are under $400.
The 92.35% factor exists because employees do not pay payroll tax on the employer half. The self employment tax calculator mirrors that by taxing only 92.35% of profit.
Self employment tax calculator worked example
Rows from the self employment tax calculator for 2026:
| Net profit | Taxable base | Social Security | Medicare | SE tax |
|---|---|---|---|---|
| $30,000 | $27,705 | $3,435.42 | $803.45 | $4,238.87 |
| $40,000 | $36,940 | $4,580.56 | $1,071.26 | $5,651.82 |
| $80,000 | $73,880 | $9,161.12 | $2,142.52 | $11,303.64 |
| $200,000 | $184,700 | $22,878.00 | $5,356.30 | $28,234.30 |
At $200,000 of profit the base is $184,700, just above the wage base, so Social Security stops at 12.4% × $184,500 = $22,878.
If you also have a W-2 job
Social Security wages from a job use up the same $184,500 wage base. If you earned $150,000 in wages, only $34,500 of self-employment earnings is still subject to the 12.4% part. The self employment tax calculator assumes no wages, so subtract them from the wage base by hand or use Schedule SE.
Additional Medicare tax
An extra 0.9% Medicare tax applies to combined wages and self-employment income above $200,000 single or $250,000 joint. The self employment tax calculator leaves it out, so add it if you are above those lines. The threshold is not indexed for inflation.
Paying it during the year
Self-employment tax is paid with income tax through quarterly estimates on Form 1040-ES. For tax year 2026 the due dates are April 15, June 15 and September 15, 2026, and January 15, 2027. The quarterly set-aside shown is one quarter of SE tax plus income tax at your rate. If you owe less than $1,000 at filing, or paid at least last year’s tax (110% if AGI was over $150,000), you generally avoid an underpayment penalty.
A self employment tax calculator result is a planning number. Your return will also use the standard deduction, the qualified business income deduction and credits, which the income tax calculator handles better.
Example: a freelance designer
A freelance designer bills $95,000 in 2026 and has $15,000 of software, equipment and home office costs, so net profit is $80,000. The taxable base is $80,000 × 92.35% = $73,880. Social Security is 12.4% of that, $9,161.12, and Medicare is 2.9%, $2,142.52, for $11,303.64 in total. Half of it, about $5,652, is deducted on Schedule 1 when figuring income tax.
In the 22% bracket the designer would plan for roughly $16,357 of income tax on top, before the standard deduction and the qualified business income deduction lower it. Setting aside about $6,900 a quarter covers both. If the designer also took a part-time W-2 job, the wages would use up some of the $184,500 wage base first.
Ways to lower self-employment tax
Only business deductions lower the base. Retirement contributions to a SEP IRA or solo 401(k) cut income tax but not self-employment tax. Track mileage, home office and equipment costs, then rerun the self employment tax calculator with the lower profit.
Estimates for education only, not tax, legal or financial advice. Check current rules with the tax authority or a qualified adviser.
Related converters and calculators
Related calculators:
- Quarterly estimated tax calculator: due dates
- Income tax calculator: federal tax
- LLC vs S corp calculator: entity choice
Sources
IRS: Topic 554, Self-employment tax; IRS: Self-employment tax (Social Security and Medicare taxes); IRS: Topic 751, Social Security and Medicare withholding rates; IRS: About Form 1040-ES, Estimated Tax for Individuals.
Questions about this calculator
What is the self-employment tax rate for 2026?
15.3%: 12.4% for Social Security on earnings up to $184,500 and 2.9% for Medicare on all earnings, applied to 92.35% of net profit.
Do I pay self-employment tax under $400?
No. If net earnings from self-employment are under $400 for the year, no self-employment tax is due.
Is half of self-employment tax deductible?
Yes. Half of the tax is an adjustment to income on Schedule 1, which lowers income tax but not the self-employment tax itself.
Does the 0.9% Additional Medicare tax apply?
Only above $200,000 single or $250,000 joint of combined wages and self-employment income. This calculator does not include it.
How much should I set aside each quarter?
A common estimate is one quarter of your self-employment tax plus income tax at your marginal rate. The calculator shows that figure.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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