"If I raise my 401(k), what happens to my paycheck?"

401(k) Paycheck Calculator for Illinois

See how raising your 401(k) contribution changes your take-home pay in Illinois — including Illinois state income tax on top of federal tax and FICA.

Your pay

Annual salary

Tax filing status

StateAdds state income tax (2025 rates). Local/city taxes and state retirement-income exclusions are not included.

Current contribution

0%6%30%

% now.

New contribution

0%10%30%

% you're considering.

Pay periods per year

Per paycheck

New take-home per paycheck

$1,632.19

Down from $0.00

Take-home drop per paycheck$76.66
Extra you save per paycheck$92.31
Extra saved per year$2,400
State income tax (per year)$2,673
Real cost per $1 saved$0.83

The magic of pre-tax: every extra dollar in your 401(k) only reduces take-home by the figure above - the rest is tax you didn't pay.

Illinois figures use 2025 rates. Flat 4.95%; no standard deduction (a personal exemption applies instead, not modeled).

How Illinois state income tax works

Illinois levies a flat 4.95% state income tax - the same rate applies no matter how much you earn. It has no standard deduction (a personal exemption or tax credit applies instead, which this estimate does not model). Flat 4.95%; no standard deduction (a personal exemption applies instead, not modeled).

Illinois state tax at different salaries

Estimated Illinois state income tax for a single filer contributing 10% to a 401(k), at 2025 rates:

Salary	Illinois state tax	Effective rate
$40,000	$1,782	4.5%
$60,000	$2,673	4.5%
$80,000	$3,564	4.5%
$100,000	$4,455	4.5%
$150,000	$6,683	4.5%

Estimate at 2025 rates assuming the standard deduction and a 10% 401(k) contribution, no other deductions or credits. Local/city taxes are not included.

Illinois paycheck FAQ

What is the Illinois state income tax rate?

Illinois has a flat income tax of 4.95%, applied to taxable income regardless of how much you earn.

Does Illinois tax 401(k) and retirement income?

Illinois fully exempts 401(k), IRA and most retirement-plan distributions from state income tax, even though it taxes wages. (Contributions you make while still working are subject to Illinois tax.)

How much Illinois state tax will I pay?

It depends on your income. As an example, a single filer earning $75,000 and contributing 10% to a 401(k) would owe about $3,341 in Illinois state income tax (about 4.5% of salary). Use the calculator above for your exact figure.

Figures current for 2026 · last reviewed June 2026 · sourced from the IRS (IRS Notice 2025-67). How we calculate & cite our data. Educational only — not financial advice.

Assumptions & notes

How is take-home estimated?

We subtract your 401(k) deferral and the standard deduction from salary, apply the 2026 federal income-tax brackets for your filing status, subtract FICA (7.65%), and - if you pick a state - add 2025 state income tax. It's an estimate: local/city taxes, credits and state retirement-income exclusions aren't modeled, so your real paycheck may differ.

Why does saving more cost less than it seems?

Traditional 401(k) contributions come out before income tax. If you're in the 22% bracket, a $100 contribution only reduces take-home by about $78 - the other $22 was tax you'd have paid anyway.

How accurate is the state tax?

We apply each state's published income-tax brackets and standard deduction. See our methodology for sources and the states still pending verification. Always confirm with your state's Department of Revenue.

These are assumptions, not guarantees. Investment returns and inflation are estimates you control - markets vary and past performance does not predict future results. Tax figures use current-year IRS numbers; your situation may differ. This tool is educational and not financial advice.

State income tax compared (all 50 states + DC)

Effective state income tax as a share of a $60,000 salary (after a 10% 401(k) contribution), filing single. Shorter bars mean more take-home. Your state (Illinois) is highlighted in gold.

Effective rate at this income only (state tax ÷ salary); graduated states rank differently at other salaries. 51 jurisdictions at 2025 rates — open any state's calculator.