McHenry County, Illinois

McHenry County, Illinois, had an estimated population of 317,751 in 2025 across 1,563 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: 317,751; 2025 estimate
Area: 1,563 km²
Density: 203; per km²
Median income: $104,802; household, ACS 2024
Median age: 40.7; years, ACS 2024

How Illinois's counties spread

Amenities & Infrastructure

Indicator	Value	In Illinois	In the US
Households with Broadband2024	95.4%	2 / 102	44 / 3,144
Median Gross Rent2024	$1,401	7 / 102	314 / 3,137
Median Home Value2024	$308,100	7 / 102	585 / 3,139
Owner-Occupied Homes2024	82.7%	12 / 102	276 / 3,144
Vacant Homes2024	3.1%	101 / 102	3,124 / 3,144

Demography

Indicator	Value	In Illinois	In the US
Aged 65 and Over2024	16.5%	91 / 102	2,528 / 3,144
American Indian & Alaska Native2024	0.0%	62 / 102	2,461 / 3,144
Asian, non-Hispanic2024	3.0%	11 / 102	338 / 3,144
Average Household Size2024people	2.6	8 / 102	498 / 3,144
Black, non-Hispanic2024	1.4%	59 / 102	1,803 / 3,144
Foreign-Born2024	9.9%	10 / 102	394 / 3,144
Hispanic or Latino2024	16.1%	8 / 102	537 / 3,144
Median Age2024years	40.7	72 / 102	1,809 / 3,144
Sex Ratio2024per 1,000 males	995	62 / 102	1,688 / 3,144
Speak a Language Other Than English2024	16.1%	11 / 102	521 / 3,144
Under 182024	22.7%	22 / 102	1,175 / 3,144
Veterans2024	5.6%	90 / 102	2,533 / 3,144
White, non-Hispanic2024	76.1%	82 / 102	1,789 / 3,144

Economy

Indicator	Value	In Illinois	In the US
Below Poverty Line2024	6.2%	98 / 102	3,012 / 3,144
Households on SNAP2024	7.4%	98 / 102	2,446 / 3,144
Income Inequality2024index	0.416	76 / 102	2,572 / 3,144
Median Household Income2024	$104,802	5 / 102	124 / 3,143
Per Capita Income2024	$49,388	4 / 102	234 / 3,144
Unemployment Rate2024	4.7%	43 / 102	1,339 / 3,144

Education

Indicator	Value	In Illinois	In the US
Bachelor's Degree or Higher2024	35.2%	13 / 102	448 / 3,144
High School or Higher2024	93.7%	21 / 102	572 / 3,144

Health Coverage

Indicator	Value	In Illinois	In the US
No Health Insurance2024	4.5%	69 / 102	2,718 / 3,144
With a Disability2024	10.1%	95 / 102	2,998 / 3,144

Population & Density

Indicator	Value	In Illinois	In the US
Population2025	317,751	6 / 102	234 / 3,144
Population Density2025/km²	203	7 / 102	270 / 3,144

Work & Commute

Indicator	Value	In Illinois	In the US
Commute by Public Transit2024	1.3%	9 / 102	298 / 3,144
Households with No Vehicle2024	3.5%	91 / 102	2,534 / 3,144
Mean Commute Time2024minutes	30.1	7 / 102	469 / 3,143
Work from Home2024	16.1%	6 / 102	324 / 3,144

Other counties of Illinois

Compare McHenry 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.