McHenry County, Illinois
Located in Illinois, McHenry County has a population of 312,591 residents and a median age of 40.7 years, making it the #233 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 6.2%. The median home value is $308,100, and the median household income is $104,802, which is 39% above the national median.
Demographics
McHenry County has a population of 312,591, making it the #233 most populous county in the US. The median age is 40.7 years, which is 4.6% above the national median.
Population Trend
Rankings →Year-over-Year Population Growth
Age & Sex Distribution
Race & Ethnicity
Nativity
Geographic Mobility (Past Year)
Economy
The median household income in McHenry County is $104,802, ranking #124 out of 3,222 counties — 39.5% above the national median. The poverty rate is 6.2% and unemployment stands at 4.7%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in McHenry County is $308,100 (+9.3% vs national). Renters pay a median of $1,401/mo and the homeownership rate is 82.7%.
Median Home Value Trend
Rankings →Household Type
Education
In McHenry County, 35.2% of adults age 25+ hold a bachelor's degree or higher, which is 4.5% above the national average, ranking #456 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in McHenry County is 79.5 years. 15.0% of adults report poor or fair health and 5.9% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
13.4% of adults in McHenry County smoke , 34.2% are obese , and 22.2% report excessive drinking. The drug overdose death rate is 18.6 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in McHenry County is 1.0 per 100,000 and the suicide rate is 10.8 per 100,000. Motor vehicle deaths occur at a rate of 8.4 per 100,000.
Homicide Rate Trend
Families & Children
7.6% of children in McHenry County live in poverty and the infant mortality rate is 4.1 per 1,000 live births. The teen birth rate is 6.4 per 1,000 females age 15–19.
Infant Mortality Trend
Civic & Transportation
Voter turnout in McHenry County is 73.4%. The mean commute time is 33.3 min, which is 20.7% above the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, McHenry County voted Republican with a margin of 5.3%. The vote was 46.6% Dem / 51.9% Rep. Compared to 2020, the margin shifted 2.8 toward Republicans .
Vote Share Over Time
About McHenry County, Illinois
McHenry County, Illinois has a total population of 312,591, making it the 233rd most populous county in the United States. The median age in McHenry County is 40.7 years, which is 4.6% above the national median of 38.9 years.
The median household income in McHenry County is $104,802, which ranks #124 of 3,222 counties nationwide. This is 39.5% above the national median of $75,149. The poverty rate is 6.2%, lower than the national rate of 12.6%. The unemployment rate stands at 4.7%.
The median home value in McHenry County is $308,100, 9.3% above the national median. Renters in McHenry County pay a median gross rent of $1,401 per month. The homeownership rate is 82.7%, compared to the national rate of 64.4%.
In McHenry County, 35.2% of residents aged 25 and older hold a bachelor's degree or higher, 4.5% above the national average of 33.7%. Health insurance coverage stands at 95.5% of the population. The average commute time for workers is 33.3 min.
McHenry County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 76.1% of the population, followed by Hispanic or Latino (16.1%) and Two or More Races (3.2%).
All data for McHenry County, Illinois comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. These figures are estimates based on survey sampling and are subject to margin of error. For the most detailed and up-to-date data, visit the Census Bureau's official data portal.