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Demographics of St. Charles County, Missouri

St. Charles County, Missouri had 426,499 people on July 1, 2025, by the Census Bureau’s estimate: +20,092 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

St. Charles County, in four figures

426,499
Population
July 1, 2025, Vintage 2025 estimate.
+4.9%
Change since July 2020
+20,092 people.
39.8 ±0.2
Median age
ACS 2020–⁠2024.
$104,692 ±$1,179
Median household income
ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

St. Charles County, Missouri's population grew 4.9% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of St. Charles County, Missouri's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

St. Charles County, Missouri's population grew 4.9% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of St. Charles County, Missouri's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1PopulationIndexUnited States
2020406,407100.0100.0
2021410,568101.0100.2
2022413,991101.9100.7
2023417,442102.7101.6
2024422,590104.0102.5
2025426,499104.9103.1

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Population of St. Charles County, Missouri on July 1 of each year, Vintage 2025
July 1PopulationChange
2020406,407+1,141
2021410,568+4,161
2022413,991+3,423
2023417,442+3,451
2024422,590+5,148
2025426,499+3,909

Age, 2020–2024

The median age is 39.8 ±0.2: for men 38.8 ±0.2 and for women 40.8 ±0.2. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in St. Charles County by age, ACS 2020–2024
AgePeopleShare
Under 522,376 ±455.4% ±<0.1
5 to 1771,004 ±1,32917.1% ±0.3
18 to 2433,722 ±9448.1% ±0.2
25 to 44110,285 ±1,41626.6% ±0.3
45 to 64106,740 ±1,47925.7% ±0.4
65 and over70,408 ±1,53417.0% ±0.4

Income and poverty, 2020–2024

Median household income is $104,692 ±$1,179, and income per person $51,051 ±$1,117, in 2024 dollars. The median is $70,702 ±$325 in Missouri and $80,734 ±$166 in the United States.

Households by income

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Households in St. Charles County by income, ACS 2020–2024
Household incomeHouseholdsShare
Under $25,00011,544 ±8497.2% ±0.5
$25,000 to $49,99920,431 ±1,15412.7% ±0.7
$50,000 to $74,99924,037 ±1,15114.9% ±0.7
$75,000 to $99,99920,231 ±1,09812.5% ±0.7
$100,000 to $149,99936,379 ±1,40422.6% ±0.9
$150,000 to $199,99923,064 ±99314.3% ±0.6
$200,000 or more25,625 ±1,14315.9% ±0.7

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in St. Charles County by age, ACS 2020–2024
AgeBelow povertyRate
All ages21,208 ±1,7795.2% ±0.4
Under 185,255 ±6125.7% ±0.7
18 to 5910,147 ±1,0754.6% ±0.5
60 and over5,806 ±5776.0% ±0.6

Housing, 2020–2024

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Housing in St. Charles County, ACS 2020–2024
MeasureSt. Charles CountyMissouri
Housing units167,163 ±1262,825,287 ±1,043
Occupied96.5% ±0.488.8% ±0.2
Vacant3.5% ±0.411.2% ±0.2
Owner occupied80.5% ±0.668.1% ±0.3
Renter occupied19.5% ±0.631.9% ±0.2
Median home value$320,800 ±$3,551$230,300 ±$880
Median gross rent$1,370 ±$21$1,033 ±$6
Median year built1994 ±11978 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in St. Charles County by Hispanic origin and race, ACS 2020–2024
OriginPeopleShare
Hispanic or Latino17,405 ±04.2% ±<0.1
White alone, not Hispanic343,925 ±87883.0% ±0.2
Black alone, not Hispanic20,824 ±7395.0% ±0.2
Asian alone, not Hispanic12,472 ±4503.0% ±0.1
American Indian and Alaska Native alone, not Hispanic135 ±53< 0.1% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic161 ±73< 0.1% ±<0.1
Some other race alone, not Hispanic1,667 ±4170.4% ±0.1
Two or more races, not Hispanic17,946 ±1,0924.3% ±0.3

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in St. Charles County by place of birth and citizenship, ACS 2020–2024
BornPeopleShare
Born in the state284,661 ±3,46068.7% ±0.8
Born in another state107,375 ±3,33125.9% ±0.8
Born a citizen outside the states3,995 ±5111.0% ±0.1
Born abroad18,504 ±1,0444.5% ±0.3
Naturalized citizens9,698 ±7972.3% ±0.2
Not citizens8,806 ±9022.1% ±0.2

St. Charles County among the counties of Missouri

3rd of 115 by population, July 2025. Every one is listed on the Missouri page.

Counties of Missouri near St. Charles County in population, July 2025
CountyJuly 2025Change since 2020
St. Louis County990,911−1.2%
Jackson County732,994+2.1%
St. Charles County426,499+4.9%
Greene County309,286+3.3%
St. Louis city278,144−7.4%
Clay County265,032+4.3%
Jefferson County233,132+2.7%
Boone County191,746+4.2%

Elsewhere on the site

Sources

Data retrieved