Illinois paycheck quick facts
| IL state income tax | 4.95% flat (since 2017) |
|---|---|
| Personal exemption (2026 est.) | $2,775 per filer / spouse / dependent |
| Local income tax | 0% (Chicago and all IL cities) |
| Effective property tax rate | ~2.1% (among highest in the US) |
| Federal income tax | 10% – 37% (2026 brackets) |
| FICA | 6.2% SS (cap $183,600) + 1.45% Medicare |
How your Illinois paycheck works
Illinois has one of the simplest state tax codes in the country: a flat 4.95% on most income. There are no progressive brackets, no standard deduction (though there is a personal exemption), and no local income tax in any Illinois city — including Chicago. Pre-tax 401(k), HSA, FSA, and health premiums all reduce Illinois taxable income, mirroring the federal treatment.
The trade-off: Illinois has among the highest property taxes in the country (~2.1% effective rate). For homeowners in Cook County or the collar counties, the property tax bill often exceeds the state income tax burden. For renters, Illinois is comparatively tax-friendly among Midwest states.
FICA: Social Security and Medicare
Every W-2 employee in the US pays FICA, regardless of state. It has two parts:
- Social Security — 6.2% of wages up to the annual wage base ($183,600 for 2026). Earnings above the cap are not taxed for Social Security.
- Medicare — 1.45% of all wages with no cap. If you earn above $200,000 (single) or $250,000 (married filing jointly), an additional 0.9% Additional Medicare Tax applies to the portion above that threshold.
Your employer pays a matching 6.2% + 1.45% (the Additional Medicare is employee-only). Self-employed workers pay both halves — known as SECA: 12.4% Social Security + 2.9% Medicare.
Federal income tax brackets (2026)
The IRS uses a progressive bracket system. The first dollars you earn are taxed at 10%, the next at 12%, and so on up to 37% for high earners. Your marginal rate is the bracket your last dollar falls into; your effective rate is your total tax divided by gross — almost always lower than your marginal rate.
| Single / MFS | MFJ | Rate |
|---|---|---|
| $0 – $12,150 | $0 – $24,300 | 10% |
| $12,150 – $49,450 | $24,300 – $98,900 | 12% |
| $49,450 – $105,700 | $98,900 – $211,400 | 22% |
| $105,700 – $201,775 | $211,400 – $403,550 | 24% |
| $201,775 – $256,225 | $403,550 – $512,450 | 32% |
| $256,225 – $640,600 | $512,450 – $768,700 | 35% |
| $640,600+ | $768,700+ | 37% |
The 2026 standard deduction reduces taxable income before brackets apply: $15,750 single, $31,500 married filing jointly, $23,625 head of household.
Pre-tax deductions that reduce your taxable income
The biggest lever you control on your paycheck is your pre-tax contributions. These come out of your gross pay before federal income tax is calculated, so every dollar contributed saves you your marginal rate's worth of tax.
- Traditional 401(k) — up to $24,500 for 2026 ($31,000 if 50+). Reduces federal taxable income but not FICA wages.
- HSA (Health Savings Account) — up to $4,400 single / $8,750 family in 2026, only available with a high-deductible health plan. Triple-tax-advantaged: pre-tax going in, tax-free growth, tax-free withdrawals for medical expenses.
- FSA (Flexible Spending Account) — up to $3,400 for 2026. Use-it-or-lose-it (with limited rollover). Pre-tax for both federal income tax and FICA.
- Employer health, dental, and vision premiums — typically pre-tax via a Section 125 cafeteria plan.
How to use this calculator
- Pick Salary or Hourly.
- Enter your annual salary (or wage + hours per period).
- Choose your pay frequency — most US employers pay bi-weekly (26 paychecks/year) or semi-monthly (24 paychecks/year).
- Pick your filing status. It controls the brackets and standard deduction.
- If you have qualifying children under 17, enter the count to claim the Child Tax Credit (up to $2,000 per child).
- Expand Pre-tax deductions if you contribute to 401(k), HSA, FSA, or pay health premiums pre-tax.
The result updates instantly. The "Take-home per paycheck" figure is what should hit your bank account; the breakdown table shows exactly where the rest goes.
Sources
The federal tax constants used here come directly from the 2026 authoritative sources:
- IRS Revenue Procedure 2025-32 — 2026 inflation-adjusted brackets, standard deduction, Child Tax Credit amounts.
- SSA Cost-of-Living Adjustment announcement — 2026 Social Security wage base ($184,500).
- IRS Publication 15-T — Federal Income Tax Withholding Methods, including Additional Medicare Tax thresholds.
- IRS Form W-4 — 2020+ five-step withholding worksheet referenced for filing-status and dependent inputs.
Calculator is provided for estimation only and does not constitute tax advice. For tax filing, consult the IRS forms above or a licensed tax professional.
How the IL personal exemption works
Unlike most states, Illinois\'s personal exemption is per-person, not a single standard deduction:
- Single filer: 1 × $2,775 = $2,775 exemption
- Married filing jointly (no kids): 2 × $2,775 = $5,550
- MFJ with two children: 4 × $2,775 = $11,100
The exemption is subtracted from federal AGI to get Illinois taxable income, on which the 4.95% rate is then applied. Higher earners may see a phaseout of the exemption.
How to increase your Illinois take-home pay
- Max your 401(k) — saves federal + Illinois tax at your marginal rate. At 22% federal + 4.95% IL, that's 26.95% marginal savings.
- HSA contributions are the most efficient — they skip federal income tax, Illinois income tax, AND FICA.
- Section-125 cafeteria plan for medical premiums — pre-tax for federal, IL, and FICA.
- Illinois doesn\'t tax retirement income. Social Security, pensions, 401(k) distributions, and IRA withdrawals are all excluded from IL income. This makes traditional 401(k) very attractive if you plan to retire in-state — you get the federal-tax deferral now plus zero IL tax on withdrawal.
- Watch your property tax. Cook County reassesses every three years; suburban Chicago counties annually. Successful appeals are common and worth pursuing.
Compare with other states: California, Pennsylvania, New York, Texas.