1099 Tax Calculator Illinois 2026
Illinois has a flat 4.95% individual income tax with no standard deduction (uses a $2,850 personal exemption instead). Self-employed workers and 1099 contractors owe Illinois state tax in addition to federal income tax (10-37%) and self-employment tax (15.3%). Use the calculator below to estimate your full 2026 tax liability and quarterly estimated payment amounts.
Net income after business expenses
Enter your income to see your tax breakdown
How Illinois taxes self-employment income
Illinois has a flat 4.95% state income tax.
Illinois has a flat 4.95% individual income tax rate. The state has no standard deduction; instead, it offers a $2,850 personal exemption per filer plus $2,850 per dependent (phased out above $250,000 single / $500,000 MFJ federal AGI).
Federal tax also applies
Regardless of state, all 1099 contractors and self-employed workers in Illinois owe federal income tax and self-employment tax. SE tax is 15.3% on net earnings (12.4% Social Security up to $184,500 in 2026, plus 2.9% Medicare with no cap). Federal income tax follows the standard bracket structure (10-37%).
The calculator above includes federal, SE, and Illinois state tax in one estimate, and breaks down quarterly estimated payments due April 15, June 15, September 15, 2026, and January 15, 2027.