Knox County, Illinois Demographics
Population trends, housing costs, income, commuting, and health, all on one page.
Knox 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.
-
B
Health Around averageLess healthy than 82% of counties in Illinois
-
D
Income Well below averageLess wealthy than 90% of counties in Illinois
-
D
Education Well below average
Source: Map AI Methodology
Population: density and quick facts
| Metric | Knox County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Population | 49,044 | 12,692,444 | 337,468,954 |
| Population density (per sq mi) | 68.1 | 219.1 | 86.4 |
| Population growth (%/yr) | -0.67% | -0.16% | 0.59% |
| Median age | 40.5 | 37.4 | 37.3 |
| Households | 20,971 | 5,035,584 | 130,235,071 |
Population in Knox County declined by 5.8% from 2009 to 2024, reaching 49,044 in 2024.
Population Growth 2009–2024
Race & Ethnicity
Age & Sex
The largest generation in Knox County is Boomers, aged 61–79, at 21.6% of residents. That is 4.7 points above Illinois as a whole.
- Gen Z 13–28 9,954 20.3% -1.0 pts
- Millennials 29–44 8,855 18.1% -3.8 pts
- Gen X 45–60 9,869 20.1% -0.3 pts
- Boomers 61–79 10,590 21.6% +4.7 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 50.1% of the people living in Knox County and men 49.9%.
- Women 50.1% Illinois 50.6%
- Men 49.9% Illinois 49.4%
How many residents match a customer profile?
Residents matching this profile
100% of everyone living in Knox County
Pick an age range and a women/men split and the figure above answers with how many residents that profile reaches.
Economy
Knox County has a the economy index of D, which means it is barely prosperous.
| Metric | Knox County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Median household income | $57,634 | $84,042 | $80,455 |
| Income growth (%/yr) | 4.50% | 4.46% | 4.80% |
| Unemployment rate | 5.1% | 5.8% | 5.2% |
The median household income in Knox County is about 31% lower than in Illinois.
Housing
| Metric | Knox County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Median home price | $28,739 | $149,936 | $248,835 |
| Median rent | $787 | $1,274 | $1,407 |
| Homeownership rate | 70.8% | 67.1% | 65.2% |
The median home price in Knox County is about 3.0 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $787 per month for that long.
Commute Time & Mobility
Commuters in Knox County spend about 28 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 116 hours, about 4.9 full days, spent commuting.
| Metric | Knox County | Illinois Avg | U.S. Average |
|---|---|---|---|
| One-way commute (min) | 14.0 | 23.6 | 22.4 |
| Round-trip commute (min) | 27.9 | 47.3 | 44.8 |
| Yearly time spent (hours) | 116 | 197 | 187 |
| Estimated yearly cost | $3,609 | $6,104 | $5,790 |
| Work from home | 5.7% | 15.9% | 15.0% |
| Highway traffic (vehicles/day) | 4,607 | 7,977 | 8,813 |
| Local road traffic (vehicles/day) | 427 | 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 Knox County is 14 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
Knox County has a education index of D, which means it is barely educated.
| Metric | Knox County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Bachelor's degree or higher | 18.6% | 34.1% | 31.6% |
| Average household size | 2.15 | 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
Knox County has a health index of B, which means it is quite healthy.
| Metric | Knox County | Illinois Avg | U.S. Average |
|---|---|---|---|
| Life expectancy (years) | 76.3 | 77.9 | 78.3 |
| Self-rated poor health | 17.6% | 15.6% | 16.3% |
| Smokers | 20.5% | 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).
Knox County, IL Compared With Nearby Counties
Knox County, IL is typical in size for this group, 49,044 residents against a local median of 48,639, so the measures below are close to a like for like comparison. Where Knox County, IL breaks from the counties next to it is median home price, sitting 53% below the local median of $61,118 at $28,739.
Commute tells the same story from another angle: 14.0 min against a local median of 18.8 min, 26% below it. The one measure here that carries a verdict is commute, and at 26% below the local median it puts Knox County, IL at the better end of the local range. The counties themselves spread $35,309 on median home price, so Knox County, IL sits at one end of an already wide local range rather than apart from it. Knox County, IL has the 4th highest median home price of the 4 areas compared here.
| Area | Population | Median household income | Median home price | Commute |
|---|---|---|---|---|
| Knox County, IL | 49,044 | $57,634 #4/4 | $28,739 #4/4 | 14.0 min #1/4 |
| Henry County, IL | 48,639 | $71,913 | $61,118 | 20.7 min |
| Fulton County, IL | 33,018 | $60,876 | $74,502 | 18.8 min |
| Peoria County, IL | 179,437 | $66,474 | $39,193 | 17.4 min |
Frequently Asked Questions
Common questions about Knox County, Illinois.
What is the population of Knox County, Illinois?
About 49,044 people live in Knox County, Illinois, in 20,971 households of 2.1 people on average. The median age is 40.5, so residents are older than the U.S. median of 37.3 by about 3 years.
How densely populated is Knox County, Illinois?
Averaged over its land area, Knox County, Illinois has 68 people per square mile, a density typical of rural areas. That is close to the U.S. average of 86.
How affordable is housing in Knox County, Illinois?
The median home costs 0.5 times the median household income ($28,739 against $57,634), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $787 a month takes about 16% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.
How common is a college degree in Knox County, Illinois?
18.6% of adults in Knox County, Illinois hold a bachelor's degree or higher (about 1 in 5), well below the U.S. share of 31.6%.
Analyze any area in the US
Get local demographics for any address, aggregated by drive time or radius, on the interactive map.
Explore the map →