Self-Employment Tax Calculator
Estimate your total self-employment tax (Social Security + Medicare), federal income tax, and quarterly estimated payments. Updated for the 2025 tax year. All calculations run in your browser -- nothing is sent to any server.
Quarterly Estimated Payments (2025)
Divide your total estimated tax into four payments to avoid underpayment penalties.
Filing Status Comparison
| Metric | Single | Married Filing Jointly | Head of Household |
|---|
How Self-Employment Tax Works
The 15.3% SE Tax
When you work for an employer, FICA taxes (Social Security + Medicare) are split 50/50 between you and your employer -- each pays 7.65%. When you are self-employed, you pay both halves: 12.4% for Social Security and 2.9% for Medicare, totaling 15.3%.
The 92.35% Rule
You don't pay SE tax on 100% of your net earnings. The IRS applies a 92.35% factor first (equivalent to net income x 0.9235). This accounts for the employer-equivalent deduction. Then the 15.3% rate applies to that adjusted amount.
Social Security Wage Cap
In 2025 the Social Security cap is $176,100. The 12.4% Social Security portion only applies to net SE income up to this threshold. Any earnings above it are exempt from the Social Security portion but still subject to the 2.9% Medicare tax.
Additional Medicare Surtax
If your total earnings exceed $200,000 (single) or $250,000 (married filing jointly), you owe an extra 0.9% Medicare surtax on income above that threshold. This brings the Medicare rate to 3.8% on high earnings.
Worked Examples
Freelance Designer -- $75,000
Gross: $75,000 with $10,000 in business expenses.
Net SE income: $65,000
SE tax base: $65,000 x 0.9235 = $60,027.50
SE tax: $60,027.50 x 0.153 = $9,184.21
Plus federal income tax on adjusted gross income, minus the deductible half of SE tax ($4,592).
Consultant -- $150,000
Gross: $150,000 with $20,000 expenses and $10,000 in health insurance.
Net SE income: $130,000
SE tax base: $130,000 x 0.9235 = $120,055
SE tax: $120,055 x 0.153 = $18,368.42
Quarterly payment: roughly $7,700 per quarter (SE + income tax combined).
Side Hustle -- $25,000
Part-time 1099 income of $25,000 with $3,000 in expenses, plus a $60,000 W-2 job.
Net SE income: $22,000
SE tax: $22,000 x 0.9235 x 0.153 = $3,107.23
Note: SE income is still subject to SE tax even with a day job. Total income affects your income tax bracket.
Common Self-Employment Deductions
| Deduction | What Qualifies | Typical Range |
|---|---|---|
| Home Office | Dedicated workspace used regularly and exclusively for business | $1,500 - $5,000+ |
| Health Insurance | Premiums for yourself, spouse, and dependents (if not eligible for employer plan) | $3,000 - $15,000+ |
| Retirement Contributions | SEP IRA (up to 25% of net SE income) or Solo 401(k) | $5,000 - $69,000 |
| Vehicle / Mileage | Business miles at IRS standard rate (70 cents/mile in 2025) | $2,000 - $10,000 |
| Equipment & Software | Computers, phones, software subscriptions used for business | $500 - $5,000 |
| Professional Development | Courses, certifications, conferences, books | $200 - $3,000 |
| Internet & Phone | Business-use percentage of home internet and phone bills | $500 - $2,000 |
| Professional Services | Accounting, legal, bookkeeping fees | $500 - $5,000 |
Frequently Asked Questions
How is self-employment tax calculated?
Self-employment tax is 15.3% of 92.35% of your net self-employment income. The 15.3% breaks down to 12.4% for Social Security (capped at $176,100 in 2025) and 2.9% for Medicare (no cap). If your income exceeds $200,000 (single) or $250,000 (married filing jointly), an additional 0.9% Medicare surtax applies. You can deduct the employer-equivalent half of SE tax from your AGI.
When are quarterly estimated tax payments due?
Quarterly estimated tax payments are due four times per year: April 15, June 15, September 15, and January 15 of the following year. If a due date falls on a weekend or holiday, the deadline moves to the next business day. Underpaying can result in a penalty, though the IRS uses a safe-harbor rule: if you pay at least 100% of last year's tax (110% if AGI > $150,000), you avoid the penalty regardless of current-year liability.
What is the self-employment tax rate for 2025?
The 2025 SE tax rate is 15.3%: 12.4% for Social Security on the first $176,100 of net earnings and 2.9% for Medicare on all net earnings. High earners above $200,000 (single) or $250,000 (MFJ) pay an additional 0.9% Medicare surtax.
Can I deduct business expenses to lower my self-employment tax?
Yes. SE tax is calculated on net self-employment income (gross minus business expenses). Common deductions include home office, health insurance, retirement contributions, equipment, mileage, and professional development. The more legitimate deductions you claim, the lower both your SE tax and income tax.
What is the difference between SE tax and income tax?
SE tax covers Social Security and Medicare (15.3%). Income tax is separate, based on your total taxable income and filing status (ranging from 10% to 37% in federal brackets). Self-employed individuals pay both. However, you can deduct the employer-equivalent half of SE tax from your adjusted gross income, which reduces your income tax.
Do I owe SE tax if I also have a W-2 job?
Yes. If your net self-employment income exceeds $400, you owe SE tax on it regardless of other employment. However, Social Security taxes paid via your W-2 job count toward the $176,100 cap. If your W-2 wages alone exceed the cap, you owe only the Medicare portion (2.9%) on your SE income.
Does this calculator store my financial data?
No. All calculations run entirely in your browser using JavaScript. No income figures, deductions, or results are sent to any server. Nothing is stored, logged, or transmitted.
Related Tools
- Paycheck Calculator -- compare W-2 take-home pay vs. 1099 self-employment
- Net Salary Calculator -- estimate salary after deductions
- Hourly to Salary Calculator -- convert hourly rate to annual equivalent
- Savings Goal Calculator -- set a quarterly tax savings target
- Compound Interest Calculator -- see how tax-deferred retirement savings grow
Privacy & Limitations
- Client-side only. No data is sent to any server. No cookies, no tracking of inputs or results.
- Estimates only. This calculator provides estimates based on 2025 IRS tax rates and standard deduction amounts. It is not tax advice. Your actual tax liability may differ due to credits, itemized deductions, AMT, and other factors.
- Federal + state estimate. State taxes use flat or approximate effective rates. Several states have progressive brackets not fully modeled here.
- Consult a tax professional. For precise tax planning, especially with complex situations (multiple income sources, dependents, credits), consult a CPA or enrolled agent.
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Self-Employment Tax Calculator FAQ
How is self-employment tax calculated?
Self-employment tax is 15.3% of 92.35% of your net self-employment income. This breaks down to 12.4% for Social Security (on income up to $176,100 in 2025) and 2.9% for Medicare (no cap). If your income exceeds $200,000 (single) or $250,000 (married filing jointly), an additional 0.9% Medicare surtax applies. You can deduct half of your SE tax from your adjusted gross income.
When are quarterly estimated tax payments due?
Quarterly estimated tax payments are due four times per year: April 15, June 15, September 15, and January 15 of the following year. If a due date falls on a weekend or holiday, the deadline moves to the next business day. You may owe a penalty if you don't pay enough by each deadline.
What is the self-employment tax rate for 2025?
The 2025 self-employment tax rate is 15.3%, composed of 12.4% for Social Security and 2.9% for Medicare. The Social Security portion applies to the first $176,100 of net earnings. The Medicare portion has no income cap, and earners above $200,000 (single) pay an additional 0.9% Medicare surtax.
Can I deduct business expenses to lower my self-employment tax?
Yes. You pay self-employment tax on your net self-employment income, which is gross income minus business expenses. Common deductions include home office expenses, health insurance premiums, retirement contributions (SEP IRA, Solo 401k), equipment, supplies, mileage, and professional development. The more legitimate deductions you claim, the lower your taxable income and SE tax.
What is the difference between self-employment tax and income tax?
Self-employment tax covers Social Security and Medicare contributions (15.3%). As a W-2 employee, your employer pays half; as self-employed, you pay both halves. Income tax is separate and depends on your taxable income and filing status. Self-employed individuals typically owe both SE tax and income tax on their earnings.
Do I have to pay self-employment tax on all my income?
You pay SE tax on 92.35% of your net self-employment earnings (this accounts for the employer-equivalent portion of the tax). If your net SE income is less than $400, you generally don't owe SE tax. The Social Security portion caps at $176,100 in 2025, but the Medicare portion applies to all earnings with no limit.
Does this calculator store my financial data?
No. All calculations run entirely in your browser using JavaScript. No income, deductions, or tax results are sent to any server. Nothing is stored or logged.