2026 Illinois withholding numbers
Illinois publishes both wage-bracket tables and an automated payroll formula in IL-700-T. The tables are labeled at least and but less than. This page uses the automated formula, which does not pick a bracket row:
The result is divided by the number of paychecks. If the allowances are at least as large as the wages, Illinois income tax is $0.00. One dollar of wages above the allowance total is taxed at 4.95%.
| Item | 2026 |
|---|---|
| Withholding rate | 4.95% |
| Line 1 allowance, annual | $2,925 |
| Line 2 allowance, annual | $1,000 |
| Wage-bracket table boundaries | At least / but less than |
| Method used here | Automated formula in IL-700-T |
Line 1 on Form IL-W-4 is the basic personal allowance. Line 2 is the additional allowance for age, blindness, or other deductions the form describes. IL-700-T values a line 1 allowance at $2,925 a year and a line 2 allowance at $1,000 a year. This page does not restate the form's checkbox rules for who may claim them.
IL-700-T does not include an employee disability or family-leave line. This page does not add one, and it does not claim that deduction is zero.
Worked example from IL-700-T
The booklet's automated-method example pays Alice $800 a week. She claims two line 1 allowances and two line 2 allowances. The booklet says to withhold $32.13. The same inputs are used below.
Alice, $800 a week, line 1 = 2, line 2 = 2
This is the worked example printed with the automated formula in the 2026 IL-700-T booklet.
Federal withholding follows IRS Publication 15-T (tax year 2026), Worksheet 1A, annualized. Annual wages are $41,600.00. Worksheet line 1g is $8,600.00, so the adjusted annual wage is $33,000.00. That wage falls in the standard percentage table row from $19,900.00 to $57,900.00. The row's base is $1,240.00 and its rate is 12%. Tentative annual federal tax is $2,812.00. Annual federal income tax before any per-paycheck extra withholding is $2,812.00.
Social Security is 6.2% of wages up to $184,500, which is $2,579.20 here. Medicare is 1.45% of all wages, $603.20. Additional Medicare is 0.9% of wages over $200,000, which is $0.00.
Illinois withholding follows the IL-700-T automated formula, not the wage-bracket tables. Annual wages are $41,600.00. Allowances exempt $7,850.00. Tax is 4.95% of what remains, $1,670.625 for the year. Wages that are not above the allowance total have no Illinois income tax.
Federal withholding follows IRS Publication 15-T (tax year 2026), Worksheet 1A, annualized. Annual wages are $41,600.00. Worksheet line 1g is $8,600.00, so the adjusted annual wage is $33,000.00. That wage falls in the standard percentage table row from $19,900.00 to $57,900.00. The row's base is $1,240.00 and its rate is 12%. Tentative annual federal tax is $2,812.00. Annual federal income tax before any per-paycheck extra withholding is $2,812.00.
| Line | This paycheck | Full year |
|---|---|---|
| Gross pay | $800.00 | $41,600.00 |
| Federal income tax | $54.08 | $2,812.00 |
| Social Security | $49.60 | $2,579.20 |
| Medicare | $11.60 | $603.20 |
| Additional Medicare | $0.00 | $0.00 |
| State income tax | $32.13 | $1,670.63 |
| Total withheld | $147.41 | $7,665.03 |
| Take-home pay | $652.59 | $33,934.97 |
How to use the result
- Put IL-W-4 line 1 in the allowance field and line 2 in the Illinois line 2 field.
- The wage-bracket tables can differ by a few cents from this formula. IL-700-T allows either method.
- Federal income tax, Social Security, and Medicare are still calculated from Publication 15-T and the FICA rates in the same data file.
Sources
Rates, brackets, deductions, and limits on this page are the 2026 figures this calculator uses (last checked 2026-10-27). The publications below are the sources for this estimate.
- IRS Publication 15-T (2026)
- Social Security and Medicare employee tax
- Social Security and Medicare employee tax
- Additional Medicare Tax
- Illinois IL-700-T
Further California forms, not used as a second set of numbers: DE 4 (employee allowances), DE 44 (employer guide), and Method A wage-bracket tables. Check a federal estimate with the IRS Tax Withholding Estimator.
Data sources: IRS Publication 15-T (2026), IL-700-T (2026) and Form IL-W-4 (2026). Last checked October 28, 2026.
Disclaimer
AuraCalcs provides estimates for informational and educational purposes only. Results use the 2026 payroll withholding methods published by the IRS and the listed state agencies and may differ from your actual paycheck, which depends on your employer's payroll system, your Form W-4 and state withholding forms, benefits elections and other factors. This is not tax, legal or financial advice. Verify with your employer's payroll department, the IRS Tax Withholding Estimator, or a qualified tax professional. The paycheck calculators estimate federal income tax, Social Security, Medicare, Additional Medicare, and state withholding for the states on these pages. They are not a bill, a filing, or a determination of tax owed.
Frequently asked questions
Where do the allowance amounts come from?
Why not the wage-bracket table?
Does Illinois add a disability tax on this page?
Can I use this for a bonus or a 401(k)?
Last reviewed: 2026-10-28