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HEAD-TO-HEAD TAX COMPARISON · 2026

COUNTRY A Illinois VS COUNTRY B Colorado

Side-by-side analysis of income tax, effective rates, and take-home pay for Illinois and Colorado in 2026.

Daniel · CountryTaxCalc Updated May 2026 Tax Comparison 2026
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OVERVIEW
The mountain escape with massive property tax savings. Colorado's 4.4% flat rate beats Illinois' 4.95%, saving $550/year at $100K income. But property tax is where Colorado dominates: 0.48% (10th-lowest nationally) vs Illinois 2.08% (2nd-highest). On $400K home: CO pays $1,920/year vs IL $8,320—CO saves $6,400 annually. Total at $100K + $400K home: Colorado saves $6,950/year. Denver's tech boom, 300+ days of sunshine, and world-class outdoor recreation make it attractive despite higher housing costs ($590K Denver vs $350K Chicago). Illinois pension crisis threatens future tax hikes; Colorado's TABOR amendment limits increases.
Section 01

The Big Picture

Top-line rates and effective take-home for a typical earner — including income tax, social contributions, and applicable surcharges.
🌽
COUNTRY A
Illinois
TAX RATE
4.95%
Flat Tax
Flat rate + high property
🏔️
COUNTRY B
Colorado
TAX RATE
4.4%
Flat Tax
Recently reduced to 4.4%
TYPICAL ANNUAL DIFFERENCE
Moving from Colorado → Illinois at $100,000
$550 income / +$6,400 property
That's CO saves $579/month total back in your pocket
Section 02

Tax Savings by Income Level

Net take-home after all income tax, social contributions, and surcharges — for a single employee with no dependents.
GROSS INCOME
🌽 IL TAX
🏔️ CO TAX
SAVINGS
10-YEAR
$50,000
$2,475
$2,200
CO saves $275
$2,750
$75,000
$3,713
$3,300
CO saves $413
$4,130
$100,000
$4,950
$4,400
CO saves $550
$5,500
$150,000
$7,425
$6,600
CO saves $825
$8,250
$250,000
$12,375
$11,000
CO saves $1,375
$13,750
$500,000
$24,750
$22,000
CO saves $2,750
$27,500
💡

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🌽

Illinois Pros & Cons

+ PROS
  • Chicago: 35 Fortune 500 HQs, established city
  • Higher median income ($88K IL vs $87K CO)
  • No altitude adjustment needed
  • More international connectivity
− CONS
  • Higher income tax (4.95% vs CO 4.4%)
  • 2nd-highest property taxes nationally (2.08%)
  • $140B pension crisis threatens future tax hikes
  • Brutal winters and population decline
🏔️

Colorado Pros & Cons

+ PROS
  • Lower income tax (4.4% vs IL 4.95%)
  • Ultra-low property tax (0.48% vs IL 2.08%—save $6,400/yr on $400K home)
  • Denver/Boulder tech boom (Google, Amazon, aerospace)
  • 300+ days sunshine, world-class skiing/hiking
− CONS
  • Denver housing expensive ($590K median vs Chicago $350K)
  • High altitude (5,280ft) affects some people
  • Traffic/infrastructure strain from rapid growth
  • Wildfire smoke season increasingly severe
FAQ

Frequently Asked Questions

How much will I save moving from Illinois to Colorado?

Income tax at $100K: CO saves $550/year (IL $4,950 → CO $4,400). Property tax is dramatic: IL 2.08% vs CO 0.48% (10th-lowest nationally). On $400K home: IL pays $8,320/year vs CO $1,920—CO saves $6,400 annually. Total at $100K + $400K home: CO saves $6,950/year ($69,500 over 10 years). But watch housing costs: Denver $590K median vs Chicago $350K—Denver $240K more expensive upfront.

Is Denver housing worth the tax savings?

Complex. Denver median $590K vs Chicago $350K—Denver $240K more expensive. Over 30-year mortgage at 7%: Denver costs $3,200/month vs Chicago $2,332 ($868 more). Annual extra: $10,416. BUT CO saves $6,950/year (income + property tax). Net: Denver costs $3,466/year MORE. HOWEVER: Denver salaries often match or exceed Chicago ($87K vs $88K median) and outdoor lifestyle is premium. Choose Denver for lifestyle + tech jobs, Chicago for pure financial math.

Can I work remotely from Colorado for an Illinois employer?

Yes—optimal strategy. Establish Colorado residency (CO driver's license, spend majority time in CO), pay Colorado taxes (4.4%), not Illinois (4.95%). At $100K: save $550/year. Add property tax savings: CO $1,920 (0.48% × $400K) vs IL $8,320 (2.08%)—save $6,400/year. Total remote work advantage: $6,950/year. Many Chicago tech/finance workers move to Denver, keep Chicago salaries ($100-150K), pay CO taxes, enjoy 300 sunny days + mountains.

How does Denver's tech scene compare to Chicago?

Denver tech scene growing fast: Google (Boulder, 1,500+ employees), Amazon (tech hub, 500+), aerospace (Lockheed Martin, Ball Aerospace), startups (Guild Education, Ibotta). Salaries: Denver $85-140K tech vs Chicago $90-150K (Chicago 5-10% higher). Chicago stronger in: fintech (Citadel, CME Group, trading firms), enterprise software. Choose Denver for: aerospace, outdoor lifestyle, growth. Choose Chicago for: peak fintech comp, established ecosystem.

What about Colorado's TABOR amendment and taxes?

Colorado's TABOR (Taxpayer Bill of Rights) amendment limits tax increases—requires voter approval for any tax/spending hikes. This keeps taxes stable (4.4% income, 0.48% property unlikely to rise dramatically). Illinois has NO such protection—legislature can raise taxes (happened 2011, 2017). Colorado's 4.4% rate recently reduced from 4.55% (2020) as TABOR refunds occur. For long-term tax stability, Colorado safer than Illinois (pension crisis threatens IL tax hikes).
From the brief
PT38.4%−9.6 vs. headline
CY17.8%incl. 60-day rule
AE 0.0%substance required
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