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Tax year 2026

California vs Illinois Income Tax — 2026

California has 10 rates from 1% to 13.3%, including a surtax above $1,000,000; Illinois charges a flat 4.95%.

California allows a $5,900 standard deduction and a $158 personal exemption credit for a single filer; Illinois allows a $2,925 personal exemption for a single filer.

A single filer earning $100,000 pays $106 less per year in Illinois than in California — $9 a month. California charges $4,911; Illinois charges $4,805.

How the two systems differ

California and Illinois income tax systems compared
CaliforniaIllinois
Tax structureGraduatedFlat rate
Top rate (any income)13.3%4.95%
Number of brackets101
Standard deduction (single)$5,900None
Personal exemption$158 credit$2,925
Local income taxesNoNo
Capital gainsTaxed as ordinary incomeTaxed as ordinary income
Population (2024)39,431,26312,710,158

More on California and Illinois

California at $100K
$4,911
4.91%
Illinois at $100K
$4,805
4.81%
Annual difference
$106
$9 a month
National ranks
43 vs 41
of 51, lowest tax first

The bill at every income

Single filer, standard deduction, no dependents. State income tax only.

California and Illinois income tax compared at seven income levels, 2026
Gross incomeCalifornia taxIllinois taxDifference
$50,000$973$2,330$1,357 less in CA
$75,000$2,665$3,568$903 less in CA
$100,000$4,911$4,805$106 less in IL
$150,000$9,561$7,280$2,281 less in IL
$250,000$18,861$12,230$6,631 less in IL
$500,000$43,543$24,750$18,793 less in IL
$1,000,000$102,301$49,500$52,801 less in IL
Annual state income tax, California versus Illinois
CA at $50,000: $973CA at $50,000$973IL at $50,000: $2,330IL at $50,000$2,330CA at $75,000: $2,665CA at $75,000$2,665IL at $75,000: $3,568IL at $75,000$3,568CA at $100,000: $4,911CA at $100,000$4,911IL at $100,000: $4,805IL at $100,000$4,805CA at $150,000: $9,561CA at $150,000$9,561IL at $150,000: $7,280IL at $150,000$7,280CA at $250,000: $18,861CA at $250,000$18,861IL at $250,000: $12,230IL at $250,000$12,230CA at $500,000: $43,543CA at $500,000$43,543IL at $500,000: $24,750IL at $500,000$24,750CA at $1,000,000: $102,301CA at $1,000,000$102,301IL at $1,000,000: $49,500IL at $1,000,000$49,500

By filing status

California and Illinois tax on $100,000 by filing status, 2026
Filing statusCaliforniaIllinoisDifference
Single$4,911$4,805$106 less in IL
Married filing jointly$1,946$4,660$2,714 less in CA
Married filing separately$4,911$4,805$106 less in IL
Head of household$2,449$4,805$2,356 less in CA

Change the assumptions

Adjust income and filing status, or swap either state. The URL updates so you can share the exact comparison.

At $100,000 as a single filer, Illinois costs $106 less per year than California — $9 a month.

California compared with Illinois at $100,000
CaliforniaIllinoisDifference
State income tax$4,911$4,805$106
Per month$409$400$9
Effective rate4.91%4.81%0.11 pts
Marginal rate9.3%4.95%4.35 pts
Standard deduction$5,900$0$5,900
Taxable income$94,100$97,075$2,975
Tax structureGraduatedFlat rate
Local income taxesNoNo

Full detail: California · Illinois · methodology

What this comparison leaves out

Sources for both states

  1. 1.California Franchise Tax BoardState revenue department
    Tax News, October 2026 — 2026 Indexing
    https://www.ftb.ca.gov/about-ftb/newsroom/tax-news/2026/10.html
    Retrieved
  2. 2.Tax FoundationResearch organization (cross-check)
    State Individual Income Tax Rates and Brackets, 2026
    https://taxfoundation.org/data/all/state/state-income-tax-rates-2026/
    Retrieved
  3. 3.Illinois Department of RevenueState revenue department
    FY 2026-15, What's New for Illinois Income Taxes
    https://tax.illinois.gov/research/publications/bulletins/fy-2026-15.html
    Retrieved · "The personal exemption amount for tax year 2026 will increase to $2,925." Also states the $500,000 / $250,000 AGI cut-off.

Figures on this page were last checked against these sources on . Found something wrong? Report it.