Illinois taxes wages at one flat rate, 4.95%, so the only thing that changes how much is withheld is the number of allowances on your IL-W-4. Each basic allowance shields $2,925 of yearly pay from withholding in 2026.
2026 tax year, verified Sources
Estimated take-home this week
$914.71
from $1,153.85 gross. You keep 79%.
2026 tax year, rules last verified November 12, 2026. An estimate, not tax advice. How we calculate
Each extra dollar you earn loses about 25¢ to taxes, but across all your pay the average is 21¢. A raise never lowers your take-home: only the dollars above a bracket line pay the higher rate.
| Annual pay | Effective | Marginal |
|---|---|---|
| $15,000 | 11.6% | 12.6% |
| $30,000 | 16.9% | 24.6% |
| $45,000 | 19.4% | 24.6% |
| $60,000 | 20.7% | 24.6% |
| $75,000 | 22.6% | 34.6% |
| $90,000 | 24.6% | 34.6% |
| $105,000 | 26.1% | 34.6% |
| $120,000 | 27.1% | 34.6% |
| $135,000 | 28.1% | 36.6% |
| $150,000 | 29.0% | 36.6% |
Same pay, W-4 and benefits; each state’s default withholding answers, no local taxes. Take-home per week:
Illinois uses a simple formula. Your employer adds up your IL-W-4 allowances (Line 1 × $2,925 plus Line 2 × $1,000), divides that by the number of paychecks in the year, subtracts it from this check’s taxable wages and withholds 4.95% of what’s left.
Because the rate is flat, a raise or overtime is taxed by Illinois at the same 4.95% as the rest of your pay. Bonuses are withheld at 4.95% too.
Illinois starts from federal taxable wages, so traditional 401(k) deferrals and Section 125 health premiums lower your Illinois withholding the same way they lower federal withholding.
| Item | 2026 amount |
|---|---|
| Income tax rate | 4.95% |
| Line 1 allowance (per year) | $2,925 |
| Line 2 allowance (per year) | $1,000 |
| Weekly value of one Line 1 allowance | $56.25 |
| Supplemental (bonus) rate | 4.95% |
Single filer, standard W-4, no benefits, paid weekly, default IL-W-4 answers. Illinois takes $46.72 of this check (4.7% of gross).
| Line | Per week | Per year |
|---|---|---|
| Gross pay | $1,000.00 | $52,000.00 |
| Federal income tax | −$78.08 | −$4,060.16 |
| Social Security | −$62.00 | −$3,224.00 |
| Medicare | −$14.50 | −$754.00 |
| Illinois income tax | −$46.72 | −$2,429.44 |
| Take-home pay | $798.70 | $41,532.40 |
Single filer, standard W-4, no benefits, no local tax. Per-week amounts; annual totals account for the Social Security wage cap.
| Salary | Gross / week | Federal | FICA | Illinois | Take-home / week | Per year |
|---|---|---|---|---|---|---|
| $30,000 | $576.92 | $27.31 | $44.14 | $25.77 | $479.70 | $24,944 |
| $40,000 | $769.23 | $50.38 | $58.84 | $35.29 | $624.72 | $32,485 |
| $50,000 | $961.54 | $73.46 | $73.56 | $44.81 | $769.71 | $40,025 |
| $60,000 | $1,153.85 | $96.54 | $88.27 | $54.33 | $914.71 | $47,565 |
| $75,000 | $1,442.31 | $147.50 | $110.33 | $68.61 | $1,115.87 | $58,025 |
| $100,000 | $1,923.08 | $253.27 | $147.11 | $92.41 | $1,430.29 | $74,375 |
| $150,000 | $2,884.62 | $475.65 | $220.68 | $140.00 | $2,048.29 | $106,511 |
Married filing jointly with two children on $100,000: $1,629.62 a week ($84,740 a year).
No Illinois city or county taxes wages. Chicago repealed its employee head tax in 2014, so a Chicago paycheck has the same deductions as one anywhere else in the state.
Illinois has no state disability, paid family leave or employee unemployment deduction. The Paid Leave for All Workers Act gives paid time off but is funded by employers, not a payroll deduction.
Illinois has reciprocal agreements with Iowa, Kentucky, Michigan and Wisconsin. If you live in one of those states and work in Illinois, file Form IL-W-5-NR so your employer withholds for your home state instead.
With one allowance, Illinois withholds 4.95% of ($1,000 − $56.25) = $46.72. Federal income tax and FICA come out too; use the calculator above for your full take-home.
Not when they go in. Traditional 401(k) deferrals are excluded from Illinois wages just as they are federally. Roth contributions are taken after tax.
No. Illinois has one flat 4.95% rate, so overtime is withheld at the same rate as regular pay. Federal withholding on a big overtime week can look higher because the federal formula annualizes each check.
No. Chicago has no income tax on wages. Your Chicago paycheck has federal, FICA and Illinois withholding only, plus any benefits you choose.
Illinois rules for the 2026 tax year, last verified November 12, 2026. Federal sources are on the methodology page.
Every state page has its own withholding formula, local taxes, payroll programs and worked examples. Compare all states.