Free Illinois Self-Employed Tax Calculator 2025

Calculate your combined federal and Illinois state income tax as a self-employed individual in 2025. Includes Self-Employment (SE) Tax at 15.3%, federal income tax (Schedule C / Form 1040), and Illinois state income tax (4.95%).

Federal Self-Employment Tax (2025)

  • SE Tax: 15.3% (12.4% Social Security + 2.9% Medicare) on 92.35% of net profit
  • Social Security wage base: $176,100 (2025)
  • Half of SE Tax is deductible above-the-line on Schedule 1
  • QBI deduction: up to 20% of qualified business income (Section 199A)
  • Standard deduction: $15,750 (Single) / $31,500 (MFJ) for 2025

Filing Deadlines

Annual deadline: April 15 (extension to October 15 available via Form 4868). Quarterly estimated tax (Form 1040-ES): Q1 Apr 15, Q2 Jun 15, Q3 Sep 15, Q4 Jan 15.

Illinois State Income Tax Brackets (2025)

  • 4.95% flat rate

More US Tax Resources

  • US Federal Tax Calculator (all states)
  • Self-Employed Tax Guides by Profession
  • US Tax Knowledge Base