Rock Island County, Illinois Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Rock Island County, IL Population Density Map and Area Scores
Area Score
Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.
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B
Health Around average
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C
Income Below average
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D
Education Well below averageBetter educated than 74% of counties in Illinois
Source: Map AI Methodology
Population: density and quick facts
| Metric | Rock Island County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Population | 142,693 | 12,692,444 | 337,468,954 |
| Population density (per sq mi) | 316.1 | 219.1 | 86.4 |
| Population growth (%/yr) | -0.33% | -0.16% | 0.59% |
| Median age | 40.4 | 37.4 | 37.3 |
| Households | 61,704 | 5,035,584 | 130,235,071 |
Population in Rock Island County declined by 2.7% from 2009 to 2024, reaching 142,693 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Rock Island County is Gen Z, aged 13–28, at 20.5% of residents. That is 0.7 points below Illinois as a whole.
- Gen Z 13–28 29,263 20.5% -0.7 pts
- Millennials 29–44 27,735 19.4% -2.4 pts
- Gen X 45–60 28,169 19.7% -0.6 pts
- Boomers 61–79 27,908 19.6% +2.6 pts
Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below Illinois, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.
Male and female share
Women are 50.5% of the people living in Rock Island County and men 49.5%.
- Women 50.5% Illinois 50.6%
- Men 49.5% Illinois 49.4%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in Rock Island County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
Rock Island County has a the economy index of C, which means it is somewhat prosperous.
| Metric | Rock Island County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Median household income | $67,544 | $84,042 | $80,455 |
| Income growth (%/yr) | 3.81% | 4.46% | 4.80% |
| Unemployment rate | 5.6% | 5.8% | 5.2% |
The median household income in Rock Island County is about 20% lower than in Illinois.
Housing
| Metric | Rock Island County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Median home price | $170,155 | $149,936 | $248,835 |
| Median rent | $888 | $1,274 | $1,407 |
| Homeownership rate | 69.7% | 67.1% | 65.2% |
The median home price in Rock Island County is about 16.0 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $888 per month for that long.
Commute Time & Mobility
Commuters in Rock Island County spend about 36 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 148 hours, about 6.2 full days, spent commuting.
| Metric | Rock Island County | Illinois Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 17.8 | 23.6 | 22.4 |
| Round-trip commute (min) | 35.6 | 47.3 | 44.8 |
| Yearly time spent (hours) | 148 | 197 | 187 |
| Estimated yearly cost | $4,602 | $6,104 | $5,790 |
| Work from home | 8.6% | 15.9% | 15.0% |
| Highway traffic (vehicles/day) | 5,660 | 7,977 | 8,813 |
| Local road traffic (vehicles/day) | 1,266 | 1,547 | 1,355 |
Fastest commutes among counties in
Illinois:
Edgar County (12.0 min), Brown County (12.7 min), Morgan County (13.1 min).
Slowest:
Calhoun County (43.8 min), Pulaski County (31.2 min), Pope County (31.0 min).
The average commute time in Rock Island County is 18 minutes, shorter than the 24 minutes in Illinois.
Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.
Education & Households
Rock Island County has a education index of D, which means it is barely educated.
| Metric | Rock Island County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 22.4% | 34.1% | 31.6% |
| Average household size | 2.23 | 2.46 | 2.53 |
Highest education index among counties in
Illinois:
DuPage County (0.4), Champaign County (0.4), Lake County (0.4).
Lowest:
Hardin County (0.2), Fayette County (0.2), Perry County (0.2).
Health
Rock Island County has a health index of B, which means it is quite healthy.
| Metric | Rock Island County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 78.0 | 77.9 | 78.3 |
| Self-rated poor health | 16.8% | 15.6% | 16.3% |
| Smokers | 18.7% | 19.2% | 19.0% |
Highest health index among counties in
Illinois:
DuPage County (0.8), Champaign County (0.8), Monroe County (0.8).
Lowest:
Alexander County (0.8), Pulaski County (0.8), Gallatin County (0.8).
Rock Island County, IL Compared With Nearby Counties
Rock Island County, IL is the 2nd largest of the 5 counties compared here, 142,693 residents against a local median of 47,453. Where Rock Island County, IL breaks from the counties next to it is median home price, sitting 37% above the local median of $124,222 at $170,155.
The counties themselves spread $106,949 on median home price, so Rock Island County, IL sits at one end of an already wide local range rather than apart from it. Rock Island County, IL has the highest median home price of the 5 areas compared here.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Rock Island County, IL | 142,693 | $67,544 #5/5 | $170,155 #1/5 | 17.8 min #3/5 |
| Scott County, IA | 174,608 | $78,775 | $168,067 | 18.0 min |
| Clinton County, IA | 46,268 | $68,145 | $164,024 | 17.2 min |
| Henry County, IL | 48,639 | $71,913 | $61,118 | 20.7 min |
| Muscatine County, IA | 42,559 | $69,993 | $84,420 | 15.6 min |
Frequently Asked Questions
Common questions about Rock Island County, Illinois.
What is the population of Rock Island County, Illinois?
About 142,693 people live in Rock Island County, Illinois, in 61,704 households of 2.2 people on average. The median age is 40.4, so residents are older than the U.S. median of 37.3 by about 3 years.
How densely populated is Rock Island County, Illinois?
Averaged over its land area, Rock Island County, Illinois has 316 people per square mile, a density typical of a mix of suburbs, small towns and farmland. That is about 3.7 times the U.S. average of 86.
Is Rock Island County, Illinois an affordable place to live?
The median home costs 2.5 times the median household income ($170,155 against $67,544), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $888 a month takes about 16% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
How educated are people in Rock Island County, Illinois?
22.4% of adults in Rock Island County, Illinois hold a bachelor's degree or higher (about 1 in 4), well below the U.S. share of 31.6%.
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