Self-Employed Tax Calculator — Illinois (2026)
Self-employed in Illinois? Your tax bill has three layers that a W-2 employee never sees in full: 15.3% self-employment tax on 92.35% of net profit, federal income tax, and Illinois state income tax. This calculator applies all three to your 2026 net profit and shows the quarterly amount you should be setting aside. Illinois uses a flat personal income tax of 4.95% applied to taxable income after a state standard deduction of $0.
Illinois Self-Employed Tax Calculator
Gross 1099 income minus business expenses.
Self-employment tax vs Illinois income tax
Self-employment tax is federal and identical in all 50 states: 12.4% Social Security up to $184,500 of net earnings plus 2.9% Medicare with no cap. Half of it is deductible against income tax, which is why the calculator subtracts it before applying brackets.
Illinois then taxes essentially the same profit figure at 4.95%. On $80,000 of net profit that adds roughly $3,680 to the bill.
Illinois has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Deductions that matter for Illinois freelancers
Net profit — not gross revenue — drives every number here. Ordinary and necessary business expenses reduce SE tax, federal tax, and Illinois tax simultaneously: the 2026 standard mileage rate of $0.67/mile, home-office square footage, software, equipment, professional insurance, and the self-employed health insurance deduction.
Retirement plans go further. A SEP-IRA or solo 401(k) reduces income tax (though not SE tax) and is often the largest single deduction available to a profitable finance contractor in Chicago.
Working for yourself in Illinois
Illinois's economy leans on finance, manufacturing, and logistics, which shapes the contractor market around Chicago — and your fixed costs. With one-bedroom rent near $1,950, a freelancer needs meaningfully more gross revenue than an employee to reach the same lifestyle, because there is no employer paying half of FICA.
Illinois is one of about a dozen states with a flat income tax — every worker pays the same 4.95% rate regardless of income level.
Local and payroll taxes Illinois adds on top
Illinois adds no state-mandated employee payroll deduction beyond FICA, so nothing extra is taken from your gross pay at the state level.
Illinois has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Nobody withholds these for you when you are self-employed in Illinois. Local wage taxes, city business licences and gross-receipts style levies are yours to register for and remit alongside your quarterly federal and state estimates.
Working across a state line from Illinois
Illinois holds income-tax reciprocity agreements with Iowa, Kentucky, Michigan and Wisconsin. If you commute between them, your wages are taxed only by your state of residence — file the exemption certificate with your employer so the wrong state is not withheld from every paycheck.
Remote and hybrid work complicates this further: most states tax income where the work is physically performed, so a Chicago resident spending part of the year at a client site in Indiana may owe a nonresident return there. Keep a day-count log if you split time between states.
The rest of your Illinois tax bill
Illinois charges a 6.25% state sales tax, homeowners pay an average effective property tax of 2.07% of market value, and the minimum wage in force during 2026 is $15.00 an hour.
Chicago's combined rate reaches 10.25%, among the highest in the country.
Income tax is only one part of a state's take. Illinois recovers revenue through sales and property tax as well, which is why headline income tax rates alone are a poor guide to how far a salary really goes. Illinois does not tax retirement income at all — Social Security, pensions, 401(k) and IRA withdrawals are exempt from the flat tax.
Illinois vs Indiana on the same salary
On a $90,000 salary, a single filer keeps about $67,690 a year in Illinois against roughly $69,445 in Indiana — a difference of $1,755, or $146 a month.
Effective combined rates are 24.8% in Illinois and 22.8% in Indiana. Set that gap against living costs: index 93 here versus 90 there, with property tax at 2.07% and 0.84% respectively.
Illinois income tax brackets 2026 (single filer)
| Taxable income | Rate |
|---|---|
| $0 and up | 4.95% |