Federal supplemental rate
Employers using the flat method withhold 22% of a bonus for federal income tax. Supplemental pay above $1 million in a year is withheld at 37%.
Salary & tax tools
Illinois Bonus Tax Calculator
Use this free Illinois bonus tax calculator to see how much of your 2026 bonus you actually keep. Enter your bonus and salary to estimate your take-home bonus after federal supplemental tax, Illinois income tax, Social Security, and Medicare.
It compares the flat 22% method with the aggregate method side by side, and shows whether you may get a refund or owe more when you file, so you can see why your bonus check looks smaller than expected.
Enter your bonus details
Enter pay before taxes. Your salary sets your tax bracket and the Social Security limit.
Most employers use the flat method when the bonus is paid on its own check. Compare both in the results.
Simple estimate: Uses 2026 federal rates (22% supplemental, 37% above $1 million), the 4.95% Illinois flat rate, and the standard deduction. It does not include IL-W-4 allowances, tax credits, or extra withholding.
Your estimated bonus
Estimated take-home bonus
$6,540.00
Flat 22% method (separate bonus check) · after all estimated taxes
Gross bonus$10,000.00
401(k) contribution$0.00
Federal income tax (22% flat)$2,200.00
Social Security$620.00
Medicare$145.00
Illinois income tax (4.95%)$495.00
Total taxes withheld$3,460.00
Take-home with flat 22% method$6,540.00
Take-home with aggregate method$5,943.30
Taxes withheld take about 34.6% of your gross bonus.
Your federal withholding is close to the tax your bonus is likely to add at filing time, so you should not expect a big refund or bill on it.
This is an estimate, not exact payroll withholding. Your W-4, IL-W-4, benefits, credits, and employer payroll settings can change your real bonus check.
How much tax is taken out of a bonus in Illinois?
In Illinois, about 34.6% of a bonus is usually withheld when it is paid on a separate check: 22% federal income tax, 6.2% Social Security, 1.45% Medicare, and 4.95% Illinois income tax. A $10,000 bonus becomes about $6,540 after tax. If your employer adds the bonus to a regular paycheck instead, more can be withheld, but the extra usually comes back as a refund when you file. Use the Illinois bonus tax calculator above for your own numbers.
How to use this Illinois bonus tax calculator
- Enter your gross bonus. Type the bonus amount before taxes, such as $5,000, $10,000, or $30,000.
- Enter your annual salary. Your regular pay sets your tax bracket and shows how much Social Security tax is left to pay.
- Pick your pay frequency and filing status. Match them to your pay stub and your tax return.
- Choose a withholding method. Use the flat 22% method for a separate bonus check, or the aggregate method if the bonus comes with regular pay.
- Add a 401(k) share if you want one. Then read your take-home bonus, every tax line, and your estimated refund or amount owed.
Tip: select the small i button next to any label to see a simple explanation.
How do I calculate taxes on a bonus?
To calculate taxes on a bonus, take out any 401(k) share, apply the federal withholding rate, and then subtract Social Security, Medicare, and Illinois income tax. Here is the full formula for the flat method.
Bonus take-home formula (flat method)
Net bonus = Gross bonus − 401(k) − Federal tax − Social Security − Medicare − Illinois tax
Federal tax = (Bonus − 401(k)) × 22%
Illinois tax = (Bonus − 401(k)) × 4.95%
Social Security = Bonus × 6.2% (up to $184,500 a year)
Medicare = Bonus × 1.45%
Federal tax = (Bonus − 401(k)) × 22%
Illinois tax = (Bonus − 401(k)) × 4.95%
Social Security = Bonus × 6.2% (up to $184,500 a year)
Medicare = Bonus × 1.45%
Example: a $10,000 bonus pays $2,200 federal, $620 Social Security, $145 Medicare, and $495 Illinois tax. That is $3,460 in tax, so you keep $6,540.
Flat method or aggregate method?
Employers use one of two federal methods. With the flat (percentage) method, a bonus paid on a separate check has a fixed 22% withheld, or 37% on supplemental pay above $1 million in a year. With the aggregate method, the bonus is added to one regular paycheck, and tax is withheld as if you earned that much every pay period. The aggregate method often withholds more because the check looks like a very large paycheck. Our calculator shows both so you can compare.
Illinois bonus tax rates for 2026
Will bonuses be taxed in 2026? Yes. Bonuses are always taxed as income, and the 2026 rates are shown below. These are the rates used in the calculator.
Social Security and Medicare
Social Security is 6.2% of pay up to $184,500. Medicare is 1.45% of all pay, plus 0.9% on pay above $200,000. Bonuses are subject to both.
Illinois income tax
Illinois has a flat income tax, and bonus withholding uses the 4.95% rate. There is no separate state bonus rate and no local income tax in Illinois.
Illinois withholding allowances
The IL-W-4 allowances you claim lower withholding on your regular pay. Many employers withhold a separate bonus check at the flat 4.95% rate, so this calculator does the same.
No SDI or paid family leave tax
Illinois does not take state disability insurance or paid family leave tax from employee pay, so none is taken from your bonus.
Total withheld
Add them up: 22% + 6.2% + 1.45% + 4.95% is about 34.6% for most Illinois workers who get a separate bonus check.
Illinois bonus take-home pay by amount (2026)
This table shows what you keep from different bonus sizes with the flat 22% method. It assumes a $75,000 salary, single filing status, and no 401(k) contribution.
| Gross bonus | Federal (22%) | Social Security | Medicare | Illinois (4.95%) | Total tax | Take-home bonus |
|---|---|---|---|---|---|---|
| $1,000 | $220.00 | $62.00 | $14.50 | $49.50 | $346.00 | $654.00 |
| $2,500 | $550.00 | $155.00 | $36.25 | $123.75 | $865.00 | $1,635.00 |
| $5,000 | $1,100.00 | $310.00 | $72.50 | $247.50 | $1,730.00 | $3,270.00 |
| $10,000 | $2,200.00 | $620.00 | $145.00 | $495.00 | $3,460.00 | $6,540.00 |
| $15,000 | $3,300.00 | $930.00 | $217.50 | $742.50 | $5,190.00 | $9,810.00 |
| $30,000 | $6,600.00 | $1,860.00 | $435.00 | $1,485.00 | $10,380.00 | $19,620.00 |
| $50,000 | $11,000.00 | $3,100.00 | $725.00 | $2,475.00 | $17,300.00 | $32,700.00 |
| $100,000 | $22,000.00 | $6,200.00 | $1,450.00 | $4,950.00 | $34,600.00 | $65,400.00 |
With the flat method, every row is taxed at about 34.6% because each tax is a fixed percentage of the bonus.
How much tax will I pay on a $10,000 bonus?
A $10,000 bonus in Illinois pays about $3,460 in taxes with the flat method and leaves you about $6,540. With the aggregate method on a $75,000 salary paid every two weeks, about $4,057 is withheld and you receive about $5,943. The difference is not extra tax. It is extra withholding that you can get back when you file.
How much will my $5000 bonus be taxed?
A $5,000 bonus is taxed about $1,730 with the flat method, so you keep about $3,270. The aggregate method withholds about $1,794 on the same salary, leaving about $3,206.
How much will a $30,000 bonus be taxed?
A $30,000 bonus pays about $10,380 in taxes with the flat method, so you keep about $19,620. Large bonuses show the biggest gap between methods. With the aggregate method, about $13,729 is withheld and you receive about $16,271, because the check pushes your pay period into higher withholding brackets.
Why was my bonus taxed at 35%?
Your bonus was not taxed at a special 35% rate. The 35% is the total of everything withheld from it. A flat 22% federal rate, plus 6.2% Social Security, 1.45% Medicare, and 4.95% Illinois tax, adds up to about 34.6%, which looks like 35% on your pay stub. The federal income tax part is only 22%.
Are bonuses taxed at 20%, 40%, or 50%?
- Are bonuses taxed at 20%? Not federally. The flat federal rate on a bonus is 22%, and payroll taxes and Illinois tax are added on top, so the total is higher than 20%.
- Are bonuses usually taxed 40%? No, but you can see about 40% withheld. In Illinois, the flat method withholds about 34.6%, while the aggregate method on a $10,000 bonus withholds about 40.6% for a $75,000 salary. It is withholding, not your real tax rate.
- Are bonuses taxed at 50%? Almost never. Even in the highest brackets, the federal withholding rate is capped at 37%, so total withholding in Illinois stays well below 50% in normal cases.
$10,000 bonus: flat method vs aggregate method by salary
Withholding and the tax you really owe can be different. This table compares take-home pay from a $10,000 bonus under the flat method, the aggregate method, and the estimated true result after you file. It assumes single filing status and pay every two weeks.
| Annual salary | Flat 22% take-home | Aggregate take-home | Estimated take-home after filing |
|---|---|---|---|
| $40,000 | $6,540.00 | $6,220.22 | $7,540.00 |
| $60,000 | $6,540.00 | $6,043.30 | $7,190.00 |
| $75,000 | $6,540.00 | $5,943.30 | $6,540.00 |
| $100,000 | $6,540.00 | $5,818.30 | $6,540.00 |
| $150,000 | $6,540.00 | $5,589.99 | $6,340.00 |
| $250,000 | $7,070.00 | $5,795.76 | $6,070.00 |
Lower earners are over-withheld by the flat 22% method and get a refund. Workers in the 24% bracket and above can owe more, because 22% is lower than their real rate. At $250,000, Social Security is already maxed out, so only Medicare applies to the bonus.
Do bonuses get taxed twice?
No. A bonus is taxed once, as income. It can feel like double taxation because the tax withheld on your bonus check is based on a flat or aggregate formula, not on your real tax bracket. When you file your return, your bonus is added to your other income and taxed at your actual rates. If too much was withheld, you get the difference back as a refund. If too little was withheld, you pay the rest. The calculator’s estimate under your results shows which one is likely for you.
How to avoid taxes on your bonus (legally)
You cannot skip tax on a bonus, but you can legally lower it. These are the most common ways.
- Send part of it to a 401(k) or 403(b). Contributions lower the bonus used for federal and Illinois income tax. For example, putting 20% of a $10,000 bonus ($2,000) into a 401(k) cuts your tax withheld from $3,460 to $2,921, which is $539 less. Social Security and Medicare still apply.
- Use payroll-deducted health savings. If you have an eligible plan, an HSA or FSA funded through payroll can reduce income tax, and in many cases payroll tax as well. Contribution limits apply.
- Adjust your W-4. If you are over-withheld every year, update your Form W-4 so more of your regular pay stays in your pocket. If you are under-withheld, add extra withholding to avoid a bill.
- Ask about timing. Some employers let you move a bonus to the next year. This can help if your income will be lower, but it has rules, so ask your payroll team and a tax professional first.
To see how these choices change your regular pay, try our Illinois paycheck calculator.
What this calculator does not include
This is a quick estimate, not a payroll run. It does not include IL-W-4 allowances, tax credits, itemized deductions, extra withholding, employer-paid gross-ups, or garnishments. Commissions and overtime paid as supplemental wages follow similar rules, so you can use it for those too, but check the result with your payroll team. Living in a state with no income tax? Try the Texas paycheck calculator or the Florida paycheck calculator. Moving to a neighboring state? See the New Jersey paycheck calculator, or compare with the California bonus tax calculator. You can also try the Georgia, North Carolina, and Virginia paycheck calculators. Federal workers can use the federal employee paycheck calculator. For extra hours instead of a bonus, use the overtime pay calculator or the 12-hour shift overtime calculator. To turn a wage into a salary, try the hourly to salary calculator. Browse more in our tax and deductions and paycheck calculators hubs, or see all calculators.
Tax rules change. This estimate is for education only and is not tax, legal, or payroll advice. For a closer estimate, use the IRS Tax Withholding Estimator or ask a tax professional. Read our disclaimer.
Illinois bonus tax calculator FAQs
How much tax is taken out of a bonus in Illinois?
About 34.6% is usually withheld from a bonus paid on a separate check: 22% federal income tax, 6.2% Social Security, 1.45% Medicare, and 4.95% Illinois income tax. A $10,000 bonus becomes about $6,540 after tax.
How much will a $30,000 bonus be taxed?
With the flat 22% method, a $30,000 bonus is taxed about $10,380 in Illinois, so you keep about $19,620. With the aggregate method on a $75,000 salary, about $13,729 is withheld and you keep about $16,271, but part of that extra withholding can come back at tax time.
Are bonuses usually taxed 40%?
No. The flat method withholds about 34.6% in Illinois. You may see close to 40% if your employer uses the aggregate method, which can withhold about 40.6% of a $10,000 bonus for a $75,000 salary. That is withholding, and any extra can be refunded when you file.
Are bonuses taxed at 20%?
Not at 20%. The flat federal withholding rate for bonuses is 22%. Social Security, Medicare, and Illinois tax come on top, so the total is about 34.6%.
How do I calculate taxes on a bonus?
Subtract any 401(k) share, withhold 22% for federal tax, then subtract 6.2% Social Security, 1.45% Medicare, and 4.95% Illinois tax. Or enter your bonus in the calculator above to do it in seconds.
Will bonuses be taxed in 2026?
Yes. Bonuses are taxed as income in 2026. The federal supplemental rate is 22% (37% above $1 million of supplemental pay in a year), and Illinois withholds at 4.95%.
How much tax will I pay on a $10,000 bonus?
About $3,460 is withheld with the flat method, leaving about $6,540. The aggregate method withholds about $4,057 on a $75,000 salary, leaving about $5,943.
Why was my bonus taxed at 35%?
Because 35% is the total of all the withholding. A 22% federal rate, 6.2% Social Security, 1.45% Medicare, and 4.95% Illinois tax add up to about 34.6%. The federal income tax rate on the bonus is still only 22%.
How much will my $5000 bonus be taxed?
With the flat method, about $1,730 is withheld and you keep about $3,270. The aggregate method withholds about $1,794 on a $75,000 salary, leaving about $3,206.
Are bonuses taxed at 50%?
Almost never. Federal bonus withholding is capped at 37%, and total withholding in Illinois stays well below 50% in normal cases. Your final tax depends on your whole income for the year.
How to avoid taxes on your bonus?
You cannot avoid tax on a bonus, but you can lower it legally. Send part of it to a 401(k), use payroll-deducted HSA or FSA benefits, adjust your W-4, or ask whether your employer can move the bonus to next year.
Do bonuses get taxed twice?
No. A bonus is taxed once as income. The withholding on your bonus check is only an advance, and your real tax is figured when you file. If too much was withheld, you get a refund.
Does Illinois have a special bonus tax rate?
No. Illinois uses its flat 4.95% withholding rate on bonus pay. The 22% and 37% rates are federal, not Illinois.
Is a bonus subject to Social Security and Medicare tax?
Yes. Bonuses count as wages, so 6.2% Social Security applies up to $184,500 of yearly pay, and 1.45% Medicare applies to all of it, plus 0.9% above $200,000.
How accurate is this Illinois bonus tax calculator?
It is a close estimate for most employees who use the standard deduction. It uses 2026 rates. Your employer’s payroll system, your W-4 and IL-W-4, and extra withholding can change your real bonus check, so the numbers may differ slightly.
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Designed & developed by
Syed Osama
Syed Osama is a digital publishing specialist who builds career metrics, financial calculators, and interactive web tools. He focuses on developing practical calculation resources to help remote workers, freelancers, and professionals make quick, accurate financial estimations.