Illinois Paycheck Calculator

Use our Illinois Paycheck Calculator to see your real take-home pay after federal tax, FICA, and Illinois’ flat 4.95% tax. Instantly calculate net pay for salary or hourly wages, bonuses, reciprocity states, Chicago commuter deductions, and annual tax planning.

$
$
(1.5x Rate)
Enter hours per pay period.
⚠️ Illinois minimum wage is $15.00/hr (2025). Your rate is low.
Federal withholding estimate. Actual varies by W-4.
Used to calculate state exemption (~$2,775/allowance).
⚠️ High allowances (>10) may cause under-withholding.
Show Advanced Options (Chicago, Reciprocity, Bonus) ▼
Residents of IA, KY, MI, WI are exempt from IL withholding (Form IL-W-5-NR).
Enables commuter benefits options.
$
Per-paycheck view shows the average impact of a one-time bonus.
%
$
Per Paycheck | Annual View
Net Pay
$0.00
Take Home Amount
Total Taxes
$0.00
Fed + IL (4.95%) + FICA
Effective Tax Rate (incl. FICA)
0.0%
Total Tax / Gross Pay
Annual Tax Planning
Est. Annual Withholding $0.00
Est. Income Tax Liability $0.00
Refund / Owe (Excl. FICA) $0.00
*Estimate assumes consistent income.
Illinois Flat Tax Note
Illinois taxes income at a flat rate of 4.95%. Unlike federal taxes, it does not use brackets.
Breakdown
View as Pay Stub
Regular Pay$0.00
Overtime Pay (1.5x)$0.00
Gross Pay $0.00
Federal Tax-$0.00
Social Security (6.2%)-$0.00
Medicare (1.45%)-$0.00
Illinois Tax (4.95%)-$0.00
Pre-Tax Deductions-$0.00
Other Deductions-$0.00
Net Pay $0.00
Earnings
Gross Wages$0.00
Taxes Withheld
Federal Income Tax$0.00
Social Security$0.00
Medicare$0.00
IL State Income Tax$0.00
Deductions
401k/Pre-Tax$0.00
Post-Tax Deductions$0.00
NET PAY DISTRIBUTION $0.00
Distribution
Pay Frequency Comparison
Frequency Gross Taxes Net Pay

The Illinois Paycheck Calculator computes estimated per-paycheck and annual payroll values by converting earnings, pay frequency, pay mode, filing status, allowances, residency selection, bonuses, deductions, and pre-tax percentages into federal income tax withholding, Illinois state income tax withholding, FICA taxes, deductions, and net pay values.

The Illinois Paycheck Calculator applies fixed constants, flat tax rates, federal tax brackets, caps, and arithmetic operations defined in the calculation logic to produce numeric outputs displayed as paycheck summaries, annual planning values, breakdown tables, and distribution charts.

Inputs Used by the Illinois Paycheck Calculator

Pay Mode (Salary / Hourly)
A categorical input that determines how gross pay per pay period is calculated. In salary mode, gross pay per period is taken directly from the gross pay input. In hourly mode, gross pay per period is calculated from hourly rate, regular hours, and overtime hours.

Pay Frequency
An integer input representing pay periods per year. Supported values are 52, 26, 24, 12, and 1. This value is used to annualize per-period income and to divide annual tax and deduction totals into per-paycheck amounts.

Gross Pay (Per Period)
A currency input used only in salary mode. This value represents gross earnings for one pay period before any deductions or taxes.

Hourly Rate
A currency input used only in hourly mode. This value represents compensation per hour.

Regular Hours
A numeric input representing regular hours worked per pay period. This value is multiplied by the hourly rate.

Overtime Hours
A numeric input representing overtime hours worked per pay period. These hours are multiplied by the hourly rate and a fixed multiplier of 1.5.

Federal Filing Status
A categorical input with values single, married filing jointly, or head of household. This selection determines which federal standard deduction constant and which federal tax bracket table are applied.

IL-W-4 Allowances
An integer input representing Illinois withholding allowances. Each allowance reduces Illinois taxable income by a fixed annual exemption value of 2,775.

Residency (Reciprocity)
A categorical input representing the worker’s state of residency. Selecting Iowa, Kentucky, Michigan, or Wisconsin applies Illinois income tax exemption. All other selections apply Illinois income tax.

Bonus / Commission Amount
A currency input representing additional income beyond base pay.

Bonus Tax Method
A categorical input determining how federal tax is applied to bonus income. “Aggregate” applies regular federal brackets to combined income. “Flat” applies a fixed 22% federal rate to the bonus portion only.

One-Time Bonus (Annual)
A boolean input determining whether bonus income is treated as a single annual amount or distributed across pay periods.

401(k) / Pre-Tax Percentage
A percentage input applied to annual gross income. The calculated amount is treated as a pre-tax deduction.

Pre-Tax Commuter / Other Deductions
A currency input representing deductions applied per pay period. This value is included in total deductions.

Chicago Work Location
A boolean input used only to reveal preset commuter deduction values. No local income tax is applied.

How the Illinois Paycheck Calculator Works

The calculation begins by determining gross pay per pay period. In salary mode, the gross pay input is used directly. In hourly mode, regular pay is calculated as hourly rate multiplied by regular hours, and overtime pay is calculated as hourly rate multiplied by overtime hours and 1.5. These values are summed to form base gross pay per period. Any bonus amount is added to this value.

Gross pay is then annualized. Base gross pay is multiplied by pay frequency. Bonus income is either multiplied by pay frequency or treated as a single annual amount depending on the one-time bonus selection. These components are summed to produce annual gross income.

Pre-tax deductions are calculated next. The pre-tax percentage is applied to annual gross income to determine annual pre-tax deductions.
Annual taxable income is calculated as:

Annual gross income − pre-tax deductions

Federal income tax is then calculated. If the bonus tax method is set to “flat,” federal tax is calculated by applying federal brackets to regular income and a fixed 22% rate to bonus income. Otherwise, federal tax is calculated by applying progressive federal brackets to total taxable income after the federal standard deduction. Standard deduction values are fixed at 14,600 for single or head of household and 29,200 for married filing jointly.

FICA taxes are calculated separately. Social Security tax is calculated at 6.2% of wages subject to an annual cap of 176,100. The base portion of wages and the bonus portion are each applied to the remaining cap space. Medicare tax is calculated at 1.45% of all annual wages with no cap.

Illinois state tax is calculated using a flat tax model. Residency selection determines whether Illinois tax is applied. If the selected residency is Iowa, Kentucky, Michigan, or Wisconsin, Illinois state tax is set to zero. Otherwise, Illinois taxable income is calculated as:

Annual taxable income − (allowances × 2,775)

Illinois taxable income is constrained to a minimum of zero. Illinois state tax is then calculated by applying a flat rate of 4.95%.

All annual taxes and deductions are divided by pay frequency to produce per-paycheck values. Net pay per paycheck is calculated as averaged gross pay per period minus federal tax, Illinois tax, Social Security tax, Medicare tax, pre-tax deductions, and other deductions.

Annual planning values are calculated using annual federal and Illinois income tax totals. FICA taxes are excluded from refund or amount-owed calculations.

Results and Metrics Explained

Net Pay
Gross pay minus all taxes and deductions for the selected view (per paycheck or annual).

Total Taxes
The sum of federal income tax, Illinois income tax, Social Security tax, and Medicare tax.

Effective Tax Rate
Total taxes divided by gross pay for the selected view, expressed as a percentage.

Federal Tax
The calculated federal income tax for the selected view.

Social Security (6.2%)
The portion of FICA tax subject to the annual wage cap.

Medicare (1.45%)
The portion of FICA tax applied to all wages.

Illinois State Tax
The calculated Illinois income tax using a flat 4.95% rate when not exempt.

Pre-Tax Deductions
The portion of income excluded before tax calculations based on the pre-tax percentage.

Other Deductions
Per-paycheck deduction amounts added to total deductions.

Estimated Annual Withholding
The annualized sum of federal and Illinois income tax withholding.

Estimated Income Tax Liability
The sum of annual federal and Illinois income tax calculated by the model.

Refund / Owe (Excluding FICA)
The numeric difference between estimated withholding and estimated income tax liability.

Interpreting the Calculation Output

Higher income inputs increase annual gross income and proportionally increase calculated taxes and deductions according to fixed rates and caps. Higher allowance values reduce Illinois taxable income numerically. Higher pre-tax percentages increase pre-tax deductions and reduce taxable income. Changing pay frequency redistributes annual totals across pay periods without changing annual totals.

Assumptions and Calculation Limits

  • Illinois income tax is calculated using a flat rate of 4.95%.
  • Illinois allowance exemptions are fixed at 2,775 per allowance.
  • Federal standard deductions are fixed at 14,600 and 29,200.
  • Social Security tax is capped at 176,100 annually.
  • Medicare tax has no income cap.
  • Reciprocity is applied only for IA, KY, MI, and WI selections.
  • No local income taxes, itemized deductions, credits, surtaxes, or phase-outs are modeled.

Estimation Disclaimer

All values are calculated using fixed constants, rates, and formulas defined in the calculator code. Results represent numerical estimates derived solely from provided inputs and programmed logic. Actual payroll calculations may differ due to rules or factors not included in this calculation model.

Related Tools & Calculators: