Illinois Paycheck Calculator: Estimate Your Take-Home Pay After Taxes

Illinois Paycheck Calculator: One Rate, No Surprises

Whether you work a shift at a Chicago distribution center, clock in at a Rockford hospital, or log hours at a Springfield office, Illinois workers share one thing in common: the same flat state income tax. Every paycheck starts with your gross earnings, subtracts federal and FICA withholding, applies the Illinois rate, and ends with your take-home pay.

With roughly 6.5 million people in the state’s civilian labor force spanning healthcare, logistics, manufacturing, and finance, that flat tax touches almost every corner of the economy. It affects hourly workers, salaried employees, and everyone in between, which is why even small changes in deductions can make a noticeable difference from one paycheck to the next.

By the end of this article, you’ll have a clearer picture of what’s withheld from an Illinois paycheck, how those deductions are calculated, and why your net pay may look a little different each pay period.

Disclaimer: This page is for informational purposes only and is not tax advice. Tax rules can change, and individual situations vary. For personal tax questions, consider speaking with a qualified tax professional.

How your Illinois paycheck is calculated: A breakdown

For tax year 2025, Illinois taxes all taxable income at a single flat rate of 4.95%, regardless of how much you earn. That rate applies to taxable income after deductions, not to your gross pay. The flat structure can make Illinois’s state income tax more predictable than a progressive system, but your full pay stub still involves several layers. Understanding each one individually helps turn your pay stub from a confusing list of numbers into a clear financial snapshot of how your paycheck comes together.

Part 1: Your gross pay before deductions

Gross pay is everything you earn before any deductions come out. For hourly workers, that includes regular hours plus any overtime. For salaried workers, it’s a fixed amount per pay period.

A few figures about minimum wage are worth knowing:

• Illinois statewide minimum wage: $15.00 per hour for workers 18 and older, effective January 1, 2025.
• Chicago workers may be subject to a higher rate: $16.60 per hour for employers with four or more employees, effective July 1, 2025.
• Tipped employees statewide may be paid $9.00 per hour, provided that tips bring the total to at least $15.00 per hour.

Part 2: Federal withholding and Form IL-W-4

Your federal income tax withholding starts with your W-4, the form you submit to your employer. It tells them how much to withhold from each paycheck based on your filing status, income level, dependents, additional income sources, and any extra withholding you choose to add. The current W-4 uses dollar amounts rather than the older allowance system.

In Illinois, you’ll also complete Form IL-W-4, the Employee’s Illinois Withholding Allowance Certificate, alongside your federal W-4. This form sets your state income tax withholding at the flat 4.95% rate separately. If you don’t submit Form IL-W-4, your employer defaults to withholding with no allowances claimed, which typically results in more state tax withheld than necessary. This can matter especially if you can claim dependents.

Part 3: Social Security and Medicare (FICA) withholding

Federal income tax withholding uses progressive brackets and is typically the largest single deduction on a paycheck. You can find the current year federal bracket information on the IRS website.

Social Security and Medicare taxes, together called FICA (Federal Insurance Contributions Act), are separate from federal income tax withholding and apply at fixed rates:

• Social Security: 6.2% of gross wages, up to the annual wage base
• Medicare: 1.45% on all covered wages

Your employer matches both of those rates on their end. There is also an Additional Medicare Tax to be aware of:

• Additionally, employers must withhold a 0.9% Additional Medicare tax once an employee’s wages exceed $200,000 in a calendar year, regardless of filing status. Final liability is reconciled at filing. This surcharge is not employer-matched.

Combined with Illinois’s flat 4.95% income tax, FICA means most workers see a meaningful portion of gross pay withheld before any other deductions are factored in.

Part 4: Illinois state income tax and its impacts

Illinois taxes all taxable income at a flat rate of 4.95% for tax year 2025. That rate applies no matter what income you earn in a year and has remained unchanged since July 1, 2017, providing some consistency for Illinois taxpayers planning their withholdings and annual returns.

It’s important to understand that the Illinois flat 4.95% tax rate applies to net income, not gross pay. To help offset that tax, for tax year 2025, the state is offering a personal exemption allowance of $2,850 per exemption. This exemption is generally allowed for the taxpayer, a spouse (if filing jointly), and each qualifying dependent (subject to certain income-based rules and phase-outs). The total exemption amount reduces taxable income before applying the 4.95% rate.

However, the exemption phases out entirely for filers with federal adjusted gross income above $250,000 (single) or $500,000 (married filing jointly). Illinois does not have a standard deduction. The personal exemption serves a similar function for state purposes.

Unlike many states, Illinois does not allow local jurisdictions to levy income taxes on wages. Workers in Chicago, Rockford, or Springfield pay only the state’s 4.95% rate on wages, with no additional city or county income tax layered on top as of tax year 2025. This can simplify paycheck calculations and eliminate the variable local rates seen in neighboring states.

Where does your income fall in Illinois? Median income overview

Median household income is a useful benchmark. It shows the midpoint of what households in the state actually earn, with half earning more and half earning less.

Illinois applies a flat 4.95% tax rate to net income, not gross pay. For tax year 2025, the state allows a personal exemption allowance of $2,850, which reduces taxable income to $57,150 (if no modifications) before applying the 4.95% rate. So, for example, consider a single filer earning $60,000 with one exemption, the estimated state income tax is ~$2,829. Actual withholding each pay period may differ based on how the IL–W–4 is completed, including allowances and any additional withholding.

For comparison, a worker earning the same $60,000 in a neighboring state with a progressive income tax may pay a different effective rate depending on which portion of income falls into which bracket. Illinois’s flat structure can mean the math stays consistent.

Note: When estimating taxes, we assume the tax year, filing status, and standard deduction/credits. All figures are estimates and may vary based on individual circumstances and time of filing.

4 ways your take-home pay can change

Your gross pay sets the ceiling, but several factors determine how much of it you actually keep. Here are four areas where your choices can make a measurable difference.

Why does take-home pay feel different in Illinois?

For most Illinois workers, the deductions on a pay stub look like this: federal income tax, FICA (6.2% Social Security + 1.45% Medicare), and Illinois state income tax at a flat 4.95%. That’s three main withholding lines before take-home pay is calculated. Workers in states with no income tax (like Texas, for instance) are likely to see only two: federal income tax and FICA.

At the same gross salary, an Illinois worker typically takes home less per year due to state-level deductions, though the impact is more moderate compared to high-tax states. Add Illinois’ cost of living — average one-bedroom rent in Chicago runs about $2,389 per month, and gas is around $4.43 per gallon, and the gap between gross pay and purchasing power can still feel noticeable.

Examples are for illustrative purposes only; actual figures depend on individual circumstances.