Illinois payroll taxes

Illinois state income tax: Flat 4.95% on taxable income. Employers withhold based on your IL-W-4 and state guidance.
FICA (federal): Social Security and Medicare apply; see the FICA section below.
Federal income tax (FIT): Withheld using IRS methods from your Form W-4 details.
State Unemployment Insurance (SUI): Employer-paid only in Illinois; employees do not pay UI from wages. Employers pay on a taxable wage base that is set annually.
Local income taxes: Illinois does not impose municipal/county wage-based income taxes on employees (see table below).
Pre-tax deductions: 401(k), HSA/FSA, and Section 125 premiums may reduce taxable wages.
Post-tax deductions: Roth 401(k), garnishments, union dues, and other after-tax items reduce net pay.

How Your Illinois Paycheck Works

Start with gross pay (salary per period, or hourly rate × hours; include overtime when due).
Subtract pre-tax deductions (traditional 401(k), HSA/FSA, cafeteria plans) to determine taxable wages.
Compute FICA (Social Security to the annual wage base; Medicare on all wages; Additional Medicare for high earners).
Calculate federal withholding using IRS methods and your W-4 elections.
Calculate Illinois withholding at 4.95% (after state adjustments/allowances from IL-W-4).
Employer separately pays Illinois SUI on the wage base—this does not reduce your take-home.
Subtract any post-tax deductions to reach net pay.

Illinois unemployment insurance (SUI) — 10-year employer snapshot

Employees do not pay Illinois UI from wages. Employers contribute on a taxable wage base at experience/new-employer rates. Values below are typical references—always confirm your annual IDES rate notice.

Year	Employee UI Rate	Employee Pays?	Employer Taxable Wage Base (approx.)	New Employer Rate (typ.)	Experienced Employer Rate Range (approx.)
2016	0%	No	$12,960	~3.55%	~0.55%–7.75%
2017	0%	No	$12,960	~3.55%	~0.55%–7.75%
2018	0%	No	$12,960	~3.55%	~0.55%–7.75%
2019	0%	No	$12,960	~3.55%	~0.55%–7.75%
2020	0%	No	$12,960	~3.55%	~0.55%–7.75%
2021	0%	No	$12,960	~3.55%	~0.55%–7.75%
2022	0%	No	$12,960	~3.55%	~0.55%–7.75%
2023	0%	No	$12,960	~3.55%	~0.85%–8.65%
2024	0%	No	$13,590	~3.95%	~0.85%–9.65%
2025	0%	No	$13,590	~3.95%	~0.85%–9.95%

Illinois salary threshold

Illinois generally follows federal FLSA white-collar rules. Exempt status requires meeting the current federal salary threshold and applicable duties tests. If either test is not met, overtime is generally owed after 40 hours in a workweek (note: some local ordinances impose higher minimum wages but do not change the state salary-basis formula).

Median Household Income — Illinois (10 years, current dollars)

Nominal values to illustrate trend; consult the latest ACS release for published figures.

Year	Median Household Income
2015	$60,400
2016	$62,000
2017	$65,000
2018	$69,200
2019	$72,200
2020	$71,500
2021	$76,000
2022	$78,800
2023	$83,600
2024	$85,400

Illinois Federal Insurance Contributions Act (FICA)

Social Security: 6.2% employee + 6.2% employer, up to the annual federal wage base.
Medicare: 1.45% employee + 1.45% employer on all wages.
Additional Medicare: 0.9% employee-only on wages above $200,000 (employer remains 1.45%).

Number of cities that have local income taxes

Illinois has no municipal/local wage-based income tax that withholds a percentage of employee earnings. Some jurisdictions may impose employer business, headcount, or occupation-related fees, but these are not paycheck percentage deductions and typically do not alter standard withholding for employees working in Illinois.

Local income tax table (employee wage tax)

City/County	Local income/occupational tax rate	Notes
Statewide	None	No city/county percentage-of-wages income tax in Illinois

Illinois Wage and Hour Laws: Overtime, Pay Frequency

Overtime: Most non-exempt employees earn 1.5× the regular rate after 40 hours/week.
Minimum wage: Illinois statewide minimum wage increases by statute; Chicago/Cook County may be higher under local ordinances.
Pay frequency: Illinois requires regular, posted paydays; commonly at least semi-monthly (many employers pay biweekly).
Final pay: Strict timelines apply at separation; unused PTO payout rules may apply based on employer policy and law.

Additional Illinois forms

IL-W-4 — Employee’s Illinois Withholding Allowance Certificate.
IL-941 — Withholding Income Tax Return (quarterly/monthly as assigned) and annual reconciliation/W-2 filing.
IDES UI registration & rate notice — Employer UI account and annual contribution rate.
Required posters — Illinois Minimum Wage, Wage Payment, VESSA, EEO, and federal postings.

FAQs — Illinois Salary Paycheck Calculator

How do I use an Illinois Salary Paycheck Calculator to estimate net pay?

Enter gross pay and pay frequency, your W-4 and IL-W-4 elections, and pre-/post-tax deductions. The calculator applies FICA, federal withholding, and Illinois’s 4.95% state tax to estimate take-home pay. Employer UI doesn’t reduce your net.

What Illinois state tax rate does the calculator use?

Illinois uses a flat 4.95% individual income tax rate. Your withholding also reflects IL-W-4 elections and any pre-tax deductions that reduce taxable wages.

Do any Illinois cities take a local income tax out of my paycheck?

No. Illinois does not have city/county percentage-of-wages income taxes. Employer business fees do not show up as a percentage deduction on employee pay stubs.

Why doesn’t my Illinois paycheck show unemployment tax like some other states?

Because Illinois UI is paid by employers only. Employees do not contribute to UI, so there is no UI line item on your pay stub.

What salary makes me exempt from overtime in Illinois?

Illinois generally follows federal FLSA rules. To be exempt, you must meet the current federal salary threshold and the duties tests. Otherwise, overtime is due after 40 hours in a week.

How often must I be paid in Illinois?

Employers must establish regular paydays—commonly semi-monthly or biweekly—and pay wages on time. Final-pay deadlines apply when employment ends.

How are bonuses and commissions taxed on an Illinois paycheck?

They’re subject to federal withholding (IRS supplemental methods), FICA, and Illinois’s 4.95% state withholding. Employer SUI continues until the employer’s wage base is met (employer expense only).

Why is my coworker’s net different even at the same salary?

Differences come from W-4/IL-W-4 elections, pre-tax benefits, Roth vs. traditional contributions, supplemental wage methods, and garnishments. These factors change taxable wages and withholding.

Does the calculator account for pre-tax benefits like HSA/FSA?

Yes. Enter those amounts; they reduce taxable wages for federal/state income tax and sometimes FICA, increasing take-home compared with after-tax deductions.

Where can I find official Illinois forms and payroll guidance?

See the Illinois Department of Revenue (IL-W-4, IL-941) and the Illinois Department of Employment Security (IDES) for UI registration and rate notices; use IRS publications for federal rules and limits.

Illinois Salary Paycheck Calculator