Self-Employment Tax for Illinois (2026)

Last updated: January 15, 2026

Illinois (IL) Key Facts

Federal S E Tax Rate

15.3%

State Income Tax Rate

4.95%

Combined S E + State Rate

20.3%

S E Tax Components

12.4% Social Security + 2.9% Medicare

How This Calculator Works in Illinois

This calculator estimates your total self-employment tax in Illinois, including the federal 15.3% SE tax and Illinois's state income tax. Enter your net SE income to see your liability.

Illinois Overview

Self-employed workers in Illinois pay the federal 15.3% SE tax plus state income tax at flat 4.95%, for a combined burden of approximately 20.3%. Illinois flat 4.95% rate makes estimated quarterly tax calculations straightforward for self-employed workers. No city income tax applies.

How Illinois Compares

Illinois's combined SE burden of 20.3% compares to Indiana at 18.4% and Wisconsin at 23.0%. State income tax creates meaningful differences between states.

StateTop RateNotes
Indiana3.05%Indiana has a state income tax on SE income rate of 3.05%.
Wisconsin7.65%Wisconsin has a state income tax on SE income rate of 7.65%.
Missouri4.8%Missouri has a state income tax on SE income rate of 4.8%.

Illinois's state income tax on SE income rate of 4.95% compares to a national average of approximately 5.04%. This is below the national average.

Tips for Illinois Residents

  • 1Federal self-employment tax is 15.3% (12.4% Social Security + 2.9% Medicare) regardless of state.
  • 2Illinois adds state income tax at flat 4.95% on self-employment income, for a combined rate of about 20.3%.
  • 3Illinois flat 4.95% rate makes estimated quarterly tax calculations straightforward for self-employed workers. No city income tax applies.
  • 4Deduct half of your SE tax on your federal return and track all business expenses to minimize net self-employment income.
  • 5Consider whether an S-Corp election could reduce your SE tax burden if your net income exceeds $50,000-$60,000.

Frequently Asked Questions

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