Self-Employment Tax Estimator
Estimate your quarterly self-employment taxes including SE tax, federal income tax, and deductible half of SE tax.
How Self-Employment Tax Works
When you work as an employee, your employer pays half of your Social Security and Medicare taxes, and the other half is withheld from your paycheck. When you are self-employed, you pay both halves yourself. This combined obligation is called self-employment tax. For 2025 the total rate is 15.3% on net self-employment earnings: 12.4% for Social Security and 2.9% for Medicare. An additional 0.9% Medicare surtax applies to earnings above certain thresholds.
What This Calculator Computes
Enter your net self-employment income (gross revenue minus business expenses), any W2 or other non-SE income, and your filing status. The calculator estimates your Social Security tax, Medicare tax (including the additional Medicare surtax if applicable), federal income tax using 2025 brackets and the standard deduction, and the deductible half of SE tax that reduces your adjusted gross income. It then shows your total annual tax liability and the quarterly estimated payment amount. If you are deciding between employment and contract work, the W2 vs 1099 Comparison Calculator can help put these tax costs in context.
Key Tax Rules for the Self-Employed
- The 92.35% factor. You only pay SE tax on 92.35% of your net self-employment income. This adjustment mirrors the fact that employers pay half of FICA taxes for their employees, and that employer portion is not taxable income to the employee.
- Social Security wage cap. The 12.4% Social Security portion only applies to combined earnings up to the annual wage base ($176,100 for 2025). If you also earn W2 wages, those wages consume part of the cap first, potentially reducing the Social Security tax owed on your self-employment income.
- Additional Medicare tax. An extra 0.9% Medicare tax applies to combined earnings (W2 wages plus SE taxable income) exceeding $200,000 for single filers or $250,000 for those married filing jointly. Only the self-employment portion above the threshold is subject to this surtax.
- Deductible half. You can deduct half of your base SE tax (Social Security plus Medicare, excluding the additional Medicare surtax) when calculating your adjusted gross income. This deduction is available whether or not you itemize.
Frequently Asked Questions
When are quarterly estimated tax payments due?
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 federal holiday, the deadline moves to the next business day. Missing a payment or underpaying can result in an estimated tax penalty.
What counts as net self-employment income?
Net self-employment income is your gross business revenue minus allowable business expenses. Common deductions include office supplies, software, professional services, a portion of home office costs, business travel, and health insurance premiums. This is the figure reported on Schedule C (line 31) or Schedule K-1 for partnerships. If you want to work backward from a target income to the rate you need to charge, the Freelance Rate Calculator can help.
Does this calculator include state taxes?
No. This estimates federal taxes only. State income tax obligations vary widely and are not included. Check your state tax authority for applicable rates and filing requirements.