04 Estimate take-home pay
Illinois paycheck calculator
Enter one paycheck's pay and the employee's Form W-4 and Form IL-W-4. See the estimated take-home pay and each tax withheld, under 2026 federal and Illinois withholding rules.
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Your result
Enter the pay date, the employee, the pay and the Form W-4 and IL-W-4 details.
You will see
- Take-home pay for this paycheck
- Each tax withheld, line by line
- The wages each tax is figured on
Your figures stay in this browser tab. Nothing is saved or sent.
What to enter
- Pay date and how often
- The date the paycheck is paid and the pay schedule. The pay date picks the tax-year rules, and only 2026 pay dates are covered. Withholding uses the standard number of paychecks a year for the schedule: 52, 26, 24 or 12.
- Who this covers
- One W-2 employee paid regular wages who lives and works in Illinois. Other states, bonuses, commissions, tips, contractors and Social Security or Medicare exemptions get no estimate.
- Gross pay
- The salary for this pay period, or the hourly rate and hours. Overtime hours use the overtime rate you enter. An hourly rate keeps its fractions of a cent until gross pay is rounded to the cent.
- Form W-4
- From the employee's 2020-or-later Form W-4: the filing status, the Step 2 box and Steps 3 and 4. Steps 3, 4(a) and 4(b) are yearly amounts; Step 4(c) is extra withholding from each paycheck. If the employee claims exemption, no federal income tax is withheld.
- Form IL-W-4
- Line 1 basic allowances, Line 2 additional allowances and Line 3 extra withholding from each paycheck.
- Deductions
- A traditional 401(k) deferral lowers the wages for federal and Illinois income tax, but Social Security and Medicare are still figured on the full pay. An HSA contribution through a cafeteria plan lowers the wages for all of them. After-tax deductions, such as Roth 401(k) contributions or a garnishment, come out of take-home pay only. Other pre-tax deductions are not covered; contribution limits are not checked.
- Year-to-date wages
- Social Security and Medicare wages this employer paid earlier in the calendar year. They decide when the $184,500.00 Social Security wage base and the $200,000.00 Additional Medicare threshold are reached. Left blank, they count as $0.
How it is calculated
- Gross pay
- Salary for the period, or Hourly rate × Hours + Overtime rate × Overtime hours, rounded to the cent
- Income tax wages
- Gross pay − Traditional 401(k) − HSA through a cafeteria plan (used for federal and Illinois income tax)
- Social Security and Medicare wages
- Gross pay − HSA through a cafeteria plan
- Adjusted annual wage
- Income tax wages × Paychecks a year + Step 4(a) − Step 4(b) − $8,600.00 ($12,900.00 if married filing jointly, nothing if the Step 2 box is checked)
- Federal income tax
- (Annual amount from the 2026 IRS percentage method table − Step 3) ÷ Paychecks a year + Step 4(c)
- Social Security
- 6.2% of Social Security and Medicare wages, up to $184,500.00 for the year
- Medicare
- 1.45% of Social Security and Medicare wages, plus 0.9% of wages over $200,000.00 for the year
- Illinois income tax
- 4.95% × (Income tax wages − (Line 1 × $2,925.00 + Line 2 × $1,000.00) ÷ Paychecks a year), not below $0, + Line 3
- Take-home pay
- Gross pay − Taxes withheld − Deductions
Illinois withholding follows the federal income tax treatment of pay, not its Social Security and Medicare treatment, under the Illinois withholding rule (86 Ill. Adm. Code 100.7000). That is why a 401(k) deferral lowers Illinois wages but not Social Security and Medicare wages.
Federal withholding follows IRS Publication 15-T Worksheet 1A and its 2026 annual tables, rounded to the cent rather than the optional whole dollar. Illinois withholding uses the automated payroll method in Booklet IL-700-T, which can differ by a few cents from the printed wage-range tables.
This is one paycheck. Withholding is not the tax owed for the year, and take-home pay times the number of paychecks is not a year of take-home pay: the Social Security wage base and the Additional Medicare threshold change later paychecks.
A month of pay on a two-week schedule is not one paycheck × 2: some months have three paydays.
It shows no employer taxes. The employee cost calculator covers those.
Worked example
An Illinois employee is paid a $2,000.00 salary every two weeks, on a 2026 pay date. Their 2020-or-later Form W-4 says single with nothing else filled in, and their Form IL-W-4 claims one basic allowance. These are example figures.
- Adjusted annual wage
- $2,000.00 × 26 − $8,600.00 = $43,400.00
- Federal income tax
- $1,240.00 + 12% × ($43,400.00 − $19,900.00) = $4,060.00 a year ÷ 26 = $156.15
- Social Security
- $2,000.00 × 6.2% = $124.00
- Medicare
- $2,000.00 × 1.45% = $29.00
- Illinois income tax
- ($2,000.00 − $112.50) × 4.95% = $93.43
- Take-home pay
- $2,000.00 − $402.58 in taxes = $1,597.42
Of $2,000.00 in gross pay, about $1,597.42 reaches the employee's account. The employer's own payroll taxes come on top of the $2,000.00 and are not in these figures.
Common questions
Why is federal withholding not my tax bracket times my pay?
Payroll uses the IRS percentage method tables, which build in a standard deduction unless the Step 2 box is checked. Withholding is a prepayment toward the year’s tax, not the tax itself, so the return can still show a refund or a balance due.
What happens when pay passes the Social Security wage base?
Enter the wages this employer already paid this year. Only the part of this paycheck up to $184,500.00 for the year is taxed for Social Security. Medicare has no cap, and 0.9% Additional Medicare tax applies to wages over $200,000.00.
Does it handle bonuses, tips or another state?
No. Bonuses, commissions, tips, work or residence outside Illinois, contractors and Social Security or Medicare exemptions are outside what it covers, and it says so instead of guessing.
Will this match the pay stub?
It should be close for the cases it covers, but payroll systems can round differently, use wage-range tables or include items this estimate does not. Check it against the actual pay stub.
Questions about payroll?
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