St. Charles County, Missouri
Located in Missouri, St. Charles County has a population of 414,535 residents and a median age of 39.8 years, making it the #178 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 5.2%. The median home value is $320,800, and the median household income is $104,692, which is 39% above the national median.
Demographics
St. Charles County has a population of 414,535, making it the #178 most populous county in the US. The median age is 39.8 years, which is 2.3% 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 St. Charles County is $104,692, ranking #125 out of 3,222 counties — 39.3% above the national median. The poverty rate is 5.2% and unemployment stands at 2.9%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in St. Charles County is $320,800 (+13.8% vs national). Renters pay a median of $1,370/mo and the homeownership rate is 80.5%.
Median Home Value Trend
Rankings →Household Type
Education
In St. Charles County, 42.7% of adults age 25+ hold a bachelor's degree or higher, which is 26.8% above the national average, ranking #205 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in St. Charles County is 79.1 years. 14.2% of adults report poor or fair health and 6.2% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
15.8% of adults in St. Charles County smoke , 36.1% are obese , and 23.0% report excessive drinking. The drug overdose death rate is 27.0 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in St. Charles County is 2.7 per 100,000 and the suicide rate is 14.4 per 100,000. Motor vehicle deaths occur at a rate of 8.1 per 100,000.
Homicide Rate Trend
Families & Children
5.6% of children in St. Charles County live in poverty and the infant mortality rate is 4.8 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 St. Charles County is 74.3%. The mean commute time is 26.8 min, which is 3.0% below the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, St. Charles County voted Republican with a margin of 17.0%. The vote was 40.8% Dem / 57.8% Rep. Compared to 2020, the margin shifted +0.5 toward Democrats .
Vote Share Over Time
About St. Charles County, Missouri
St. Charles County, Missouri has a total population of 414,535, making it the 178th most populous county in the United States. The median age in St. Charles County is 39.8 years, which is 2.3% above the national median of 38.9 years.
The median household income in St. Charles County is $104,692, which ranks #125 of 3,222 counties nationwide. This is 39.3% above the national median of $75,149. The poverty rate is 5.2%, lower than the national rate of 12.6%. The unemployment rate stands at 2.9%.
The median home value in St. Charles County is $320,800, 13.8% above the national median. Renters in St. Charles County pay a median gross rent of $1,370 per month. The homeownership rate is 80.5%, compared to the national rate of 64.4%.
In St. Charles County, 42.7% of residents aged 25 and older hold a bachelor's degree or higher, 26.8% above the national average of 33.7%. Health insurance coverage stands at 95.8% of the population. The average commute time for workers is 26.8 min.
St. Charles County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 83.0% of the population, followed by Black (non-Hispanic) (5.0%) and Two or More Races (4.3%).
All data for St. Charles County, Missouri 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.