Mercer County, Illinois

Mercer County, Illinois, had an estimated population of 15,229 in 2025 across 1,454 km². The figures below come from the US Census Bureau's population estimates and the American Community Survey, each shown with its own vintage and its rank among Illinois's counties and nationally.

Population: 15,229; 2025 estimate
Area: 1,454 km²
Density: 10; per km²
Median income: $74,182; household, ACS 2024
Median age: 44.7; years, ACS 2024

How Illinois's counties spread

Amenities & Infrastructure

Indicator	Value	In Illinois	In the US
Households with Broadband2024	90.5%	17 / 102	714 / 3,144
Median Gross Rent2024	$786	66 / 102	2,204 / 3,137
Median Home Value2024	$146,700	41 / 102	2,289 / 3,139
Owner-Occupied Homes2024	83.8%	10 / 102	184 / 3,144
Vacant Homes2024	9.9%	61 / 102	2,208 / 3,144

Demography

Indicator	Value	In Illinois	In the US
Aged 65 and Over2024	21.9%	30 / 102	1,010 / 3,144
American Indian & Alaska Native2024	0.1%	18 / 102	1,566 / 3,144
Asian, non-Hispanic2024	0.4%	66 / 102	2,008 / 3,144
Average Household Size2024people	2.3	50 / 102	2,177 / 3,144
Black, non-Hispanic2024	0.6%	78 / 102	2,332 / 3,144
Foreign-Born2024	1.1%	73 / 102	2,595 / 3,144
Hispanic or Latino2024	3.4%	49 / 102	2,058 / 3,144
Median Age2024years	44.7	18 / 102	743 / 3,144
Sex Ratio2024per 1,000 males	979	73 / 102	2,047 / 3,144
Speak a Language Other Than English2024	2.8%	59 / 102	2,414 / 3,144
Under 182024	20.8%	65 / 102	1,980 / 3,144
Veterans2024	8.4%	25 / 102	856 / 3,144
White, non-Hispanic2024	93.1%	32 / 102	317 / 3,144

Economy

Indicator	Value	In Illinois	In the US
Below Poverty Line2024	8.9%	83 / 102	2,581 / 3,144
Households on SNAP2024	9.9%	87 / 102	1,938 / 3,144
Income Inequality2024index	0.414	79 / 102	2,632 / 3,144
Median Household Income2024	$74,182	27 / 102	898 / 3,143
Per Capita Income2024	$39,391	27 / 102	897 / 3,144
Unemployment Rate2024	3.2%	85 / 102	2,324 / 3,144

Education

Indicator	Value	In Illinois	In the US
Bachelor's Degree or Higher2024	20.9%	50 / 102	1,765 / 3,144
High School or Higher2024	93.9%	16 / 102	513 / 3,144

Health Coverage

Indicator	Value	In Illinois	In the US
No Health Insurance2024	4.6%	65 / 102	2,694 / 3,144
With a Disability2024	13.0%	86 / 102	2,435 / 3,144

Population & Density

Indicator	Value	In Illinois	In the US
Population2025	15,229	68 / 102	2,079 / 3,144
Population Density2025/km²	10	78 / 102	2,010 / 3,144

Work & Commute

Indicator	Value	In Illinois	In the US
Commute by Public Transit2024	0.0%	87 / 102	2,161 / 3,144
Households with No Vehicle2024	2.8%	97 / 102	2,833 / 3,144
Mean Commute Time2024minutes	28.1	16 / 102	764 / 3,143
Work from Home2024	10.1%	26 / 102	1,147 / 3,144

Other counties of Illinois

Compare Mercer County against every other county on a map, add layers and run a scatter — open the atlas. Sources and vintages for every figure on this page are listed under datasets, or browse all 3,144 counties.