Illinois Bonus Tax Calculator
Your Bonus Tax Breakdown
Step-by-Step Guide to Using the Calculator
This calculator simplifies bonus tax calculations for 2025. You enter your bonus amount and filing status. The tool applies Illinois and federal tax rates automatically. It then displays your total tax withheld and net pay. Follow these steps to get accurate results fast.
- Step 1: Input your gross bonus amount.
- Step 2: Select filing status (single, married, etc.).
- Step 3: Click “Calculate” for instant tax breakdown.
- Step 4: Review Illinois tax, federal tax, and take-home pay.
Welcome to the Illinois Bonus Tax Calculator 2025
This tool helps you calculate the taxes on your bonus in Illinois for 2025. Illinois taxes bonuses as supplemental income. The state applies a flat income tax rate of 4.95%. Federal supplemental tax rates also affect your take-home pay. Use this calculator to see your net bonus quickly.
- Simple inputs include bonus amount and filing status.
- Results show Illinois state tax, federal tax, and net pay.
- Updated for 2025 tax laws and rates.
Illinois Bonus Tax Rates for 2025
Illinois uses a flat 4.95% state income tax rate for all bonuses in 2025. Federal taxes follow supplemental wage rules. Bonuses face a 22% federal rate unless they exceed $1 million, then 37%. Social Security (6.2%) and Medicare (1.45%) also apply up to wage limits. This table breaks down the rates clearly.
| Tax Type | Rate | Applies To |
|---|---|---|
| Illinois State Tax | 4.95% | All bonuses |
| Federal Tax | 22% or 37% | Up to/over $1 million |
| Social Security | 6.2% | Up to $168,600 (2025 cap) |
| Medicare | 1.45% | All wages; 2.35% over $200,000 |
Example Calculation for a $5,000 Bonus in 2025
A $5,000 bonus shows how taxes reduce your pay. Illinois withholds 4.95%, or $247.50. Federal tax at 22% takes $1,100. Social Security takes $310, and Medicare takes $72.50. Your net pay totals $3,270 after all deductions.
- Gross bonus: $5,000.
- Illinois tax: $247.50.
- Federal tax: $1,100.
- Net pay: $3,270 (single filer, under wage caps).
How Illinois Taxes Bonuses in 2025
Illinois treats bonuses as supplemental wages. The state withholds 4.95% from your bonus for income tax. Employers can use the percentage method or aggregate method for federal taxes. Federal supplemental tax rates are 22% for bonuses up to $1 million and 37% above that. Your net bonus depends on these combined taxes.
- Illinois flat tax rate: 4.95%.
- Federal tax rate: 22% or 37% based on bonus size.
- No local income taxes apply in Illinois.
Recent Illinois Tax Changes for 2025
Illinois updated tax laws for 2025. The state keeps its 4.95% flat income tax rate. Net operating loss deductions rose to $500,000 for businesses. Grocery tax drops to 0% starting January 1, 2026, but not for 2025 bonuses. These changes ensure accurate bonus tax calculations.
- Flat tax rate unchanged at 4.95%.
- NOL cap increased from $100,000 to $500,000.
- No local income tax affects bonuses.
Factors Affecting Your Bonus Tax in 2025
Several factors change your bonus tax amount. Filing status adjusts federal tax brackets.
Bonus size impacts federal rates (22% or 37%). Yearly earnings affect Social Security and Medicare caps. Illinois keeps its 4.95% rate constant regardless of these factors.
- Single filers face higher federal rates than married filers.
- Earnings over $168,600 skip Social Security tax.
- High earners (over $200,000) pay extra 0.9% Medicare tax.
Comparing Illinois Bonus Tax to Other States
Illinois’s 4.95% flat rate differs from other states. Neighboring Wisconsin uses graduated rates up to 7.65%.
Iowa applies rates from 0.33% to 6%. Kentucky matches Illinois with a 4.5% flat rate.
Federal supplemental rates remain consistent across states.
| State | Tax Rate | Notes |
|---|---|---|
| Illinois | 4.95% flat | No local income tax |
| Wisconsin | 3.54%–7.65% | Graduated rates |
| Iowa | 0.33%–6% | Graduated rates |
| Kentucky | 4.5% flat | Similar to Illinois |
Tips to Maximize Your Bonus Take-Home Pay
You can reduce taxes on your 2025 bonus. Contribute to a 401(k) to lower taxable income.
Use pre-tax deductions like health savings accounts. Spread bonuses across paychecks if possible.
Consult a tax professional for personalized advice.
- 401(k) contributions cut federal taxable income.
- HSAs reduce both federal and state tax.
- Splitting bonuses may avoid higher tax brackets.