Illinois vs 
Idaho
Take-home pay after federal tax, state income tax, and FICA — calculated with the same engine as our paycheck calculator.
By Sammy S. · Founder · AuthorUpdated for 2026
Winner at $100k
Illinois
Extra take-home / year
$350
Per month
$29
Over 10 years
$3,500
Moving from Idaho → Illinois at $100,000
Metric vs metric
Lower tax and cost figures generally favor the highlighted cell. Rate structure notes sit under each state's calculator link.
| Metric | Illinois | Idaho |
|---|---|---|
| Income tax | 4.95% · Flat 4.95% | 5.30% · Flat 5.30% |
| Combined sales tax | ~8.98% | ~6.03% |
| Effective property tax | ~1.88% | ~0.5% |
| Cost of living index | 95.1 | 101.7 |
| Median household income | $77,800 | $70,800 |
| Unemployment rate | 4.5% | 3% |
Dig into each state's paycheck
Illinois rate structure
Flat 4.95% state income tax on taxable wages (before credits).
Idaho rate structure
Flat 5.30% state income tax on taxable wages (before credits).
Overview
Illinois (Flat 4.95%) vs Idaho (Flat 5.30%). At $100,000 gross (single), Illinois typically leaves you with about $350 more take-home than Idaho after federal, state, and FICA. Sales tax ~8.98% vs ~6.03%; property tax ~1.88% vs ~0.5%. Median household income (ACS 2024): $77,800 vs $70,800.
Take-home by income
Net pay after federal income tax, state income tax, and FICA — single filer, standard deduction, no dependents (2026). Advantage is take-home in Idaho minus Illinois.
| Gross | Illinois take-home | Idaho take-home | Advantage |
|---|---|---|---|
| $50,000 | $39,880 | $39,705 | −$175 |
| $75,000 | $57,880 | $57,618 | −$262 |
| $100,000Headline | $74,230 | $73,880 | −$350 |
| $150,000 | $106,366 | $105,841 | −$525 |
| $200,000 | $139,027 | $138,327 | −$700 |
| $500,000 | $315,727 | $313,977 | −$1,750 |
Assumptions: single filer, standard deduction, no dependents, tax year 2026. At $100k: FICA ≈ $7,650 in both states; effective total tax rate ≈ 25.8% in Illinois vs 26.1% in Idaho. Local city taxes are not included unless noted.
$100k tax breakdown: Illinois vs Idaho
Where a $100,000 paycheck goes after federal income tax, state income tax, and FICA (2026, single filer).
| Line item | Illinois | Idaho |
|---|---|---|
| Gross pay | $100,000 | $100,000 |
| Federal income tax (est.) | $13,170 | $13,170 |
| State income tax | $4,950 | $5,300 |
| FICA (SS + Medicare) | $7,650 | $7,650 |
| Take-home pay | $74,230 | $73,880 |
| Effective total tax rate | 25.8% | 26.1% |
| Monthly take-home | $6,186 | $6,157 |
Federal estimates can differ slightly between states when state interactions affect taxable income. Combined sales tax ~8.98% (Illinois) vs ~6.03% (Idaho); effective property tax ~1.88% vs ~0.5%.
Pros & cons: Illinois vs Idaho
Tax structure, living costs, and lifestyle trade-offs beyond the paycheck number.
Illinois
Pros
- Lower top/marginal state rate (Flat 4.95%) than Idaho (Flat 5.30%)
- About $350/year more take-home at $100k gross (single) vs Idaho
- Lower cost of living index (95.1 vs 101.7; 100 = US average)
- Higher median household income ($77,800 ACS 2024 vs $70,800)
Cons
- −Higher combined sales tax (~8.98% vs ~6.03% in Idaho)
- −Higher effective property tax (~1.88% vs ~0.5% in Idaho)
- −Higher unemployment rate (4.5% vs 3%)
Idaho
Pros
- Lower combined sales tax (~6.03% vs ~8.98% in Illinois)
- Lower effective property tax (~0.5% vs ~1.88% in Illinois)
- Lower unemployment rate (3% vs 4.5%)
Cons
- −State income tax (Flat 5.30%) reduces take-home vs a $0-income-tax peer
- −Roughly $350/year less take-home at $100k vs Illinois
- −Higher cost of living index (101.7 vs 95.1; 100 = US average)
- −Lower median household income ($70,800 ACS 2024 vs $77,800)
Who wins when
Quick read on when each state is the better fit — beyond the headline tax number.
- Illinois wins on take-home pay at every salary band in our ladder (single filer, standard deduction).
- Illinois: Lower top/marginal state rate (Flat 4.95%) than Idaho (Flat 5.30%)
- Illinois: About $350/year more take-home at $100k gross (single) vs Idaho
- Idaho: Lower combined sales tax (~6.03% vs ~8.98% in Illinois)
- Idaho: Lower effective property tax (~0.5% vs ~1.88% in Illinois)
How we calculate Illinois vs Idaho
Tax engine. Federal income tax uses 2026 IRS brackets and the standard deduction for a single filer. FICA includes Social Security and Medicare employee shares. State income tax applies Illinois's and Idaho's rules as modeled in our US calculator (Flat 4.95% vs Flat 5.30%).
What's included. Wage income only — no capital gains, self-employment tax, itemized deductions, credits, or local city wage taxes (e.g. NYC) unless noted. Sales tax (~8.98% vs ~6.03%) and property tax (~1.88% vs ~0.5%) are context metrics, not subtracted from the take-home ladder.
Cost of living. COL indexes (95.1 vs 101.7, 100 = US average) and median household income ($77,800 vs $70,800) help interpret whether a paycheck win buys more in real life. For city-level equivalent salary, use the Illinois → Idaho relocation calculator.
Frequently asked questions
Common questions about Illinois vs Idaho taxes, take-home pay, and relocation.
Moving Illinois → Idaho?
Model cost-of-living equivalent salary, or open each state's paycheck calculator with your filing status and deductions.
Related tools
Estimates only for tax year 2026. Not tax advice — verify with your state tax agency or a CPA before relocating. Figures assume a single filer with the standard deduction and no dependents.