St. Charles: Demographics & People
St. Charles is home to 71,508 people, in 30,362 households. Population grew 0.7% from 71,048 (2022) to 71,508 (2024). Median age 38.6 years. (1.2y younger than St. Charles County; 0.6y younger than Missouri). Children under 18 are 18% of the population. Population is 78% White (non-Hispanic) and 7% Black. The community is somewhat diverse (Simpson index 0.33). 58% of households are family-led. County is gaining 5,845 residents per year (2022-2023). County health: 36% adult obesity, 16% smoke.
- 2.4 people per household.
- 42% non-family households (singles, roommates).
Population & Trend
Population grew 0.7% from 71,048 (2022) to 71,508 (2024) — close to the U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~71,973 (extrapolated at 0.3%/yr trend). Census Bureau Vintage estimate: 72,599.
| Census data vintage | 2024 |
|---|---|
| Population | 405,262 people |
| Annual growth rate · Population change | 0.7% |
| Annual growth rate · Population (2022) | 71,048 |
| Annual growth rate · Population (2024) | 71,508 |
| Annual growth rate · Population growing | Yes |
| Annual growth rate · Trend category | stable |
| Population | 71,508 people |
| Population Estimate | 72,599 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 38.6y is 0.3 years younger than the U.S. median (38.9y). Children under 18 make up 18% — below the U.S. share of ~22%.
| Age Summary · Median age | 38.6 years (vs Missouri 39.2y) |
|---|---|
| Age Summary · Children Pct | 17.7% |
| Age Summary · Character | family-oriented |
| Population under 18 | 12,642 |
| Median age | 38.6 years (vs Missouri 39.2y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 71,508 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.33 (0 = single group, 1 = perfectly even distribution); this is read as somewhat diverse.
| White residents | 56,366 |
|---|---|
| Black residents | 5,448 |
| Asian residents | 2,825 |
| Hispanic or Latino residents | 4,686 |
| Diversity Index · Diversity index (Simpson) | 32.6% |
| Diversity Index · Diversity label | somewhat diverse |
| Diversity Index · Groups counted | 4 |
| Diversity Index · Largest group share | 81.3% |
| Asian population | 3.8% |
| Black population | 7.2% |
| Hispanic or Latino population | 6.5% |
| White (non-Hispanic) population | 77.7% |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Ancestry
Self-reported ancestry from Census ACS — what residents report as their ethnic origin, separate from race. Counts can exceed population because people can list multiple ancestries.
Top (8)
Citizenship & Origin
Where residents were born and their citizenship status (Census ACS). 1.4% are foreign-born — below the U.S. average of 13.9%. 6% have naturalized to U.S. citizenship.
| Residents born in this state | 46,378 |
|---|---|
| Residents born in another state | 19,710 |
| Share born in this state | 64.9% |
| Share born in another state | 35.1% |
| Native-born U.S. citizens | 27.6% |
| Foreign-born residents | 1.4% |
| Naturalized citizens | 6.2% |
| Total foreign-born residents | 3,883 |
| From Europe | 602 |
| From Asia | 16 |
| From Africa | 1,630 |
| From Latin America | 103 |
| Census Foreign Born · Central America | 26 |
Households & Family Composition
30,362 households. Averaging 2.2 people each — smaller than the U.S. average of 2.5. 58% are family households — below the U.S. share of ~65%. Of 17,721 families, 27% are married couples with children.
| Children under 18 | 12,433 |
|---|---|
| Total families | 17,721 |
| Married couples with children | 4,825 |
| Single-parent households | 520 |
| Average household size | 2.19 |
| Women who gave birth (past year) | 13.9% |
| Grandparents living with grandchildren | 710 |
| Grandparents responsible for grandchildren | 210 |
| Family households | 17,746 households |
| Households that are families | 58.4% |
| Total households | 30,362 households |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Residential Stability & Migration
How long residents have lived here and where they came from. 14.2% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 5,845 residents per year on net (IRS migration data).
| Moved within the county (past year) | 14.2% |
|---|---|
| Migration · People moving in (annual) | 403,338 |
| Migration · People moving out (annual) | 397,493 |
| Migration · Net migration (in − out) | 5,845 |
| Migration · Population growing | Yes |
| Migration · Year | 2022-2023 |
Sources: IRS SOI Migration 2021-2022 · Refreshed 2026-04-12
Disability
Census ACS measures self-reported functional limitations — vision, hearing, mobility, cognitive, self-care, or independent-living. The U.S. baseline disability rate is about 12–13%; rates trend higher with median age.
| Residents with a disability | 3,940 |
|---|---|
| Disability rate | 5.6% |
Group Quarters
Group quarters are non-household living arrangements counted by the Census — college dormitories, nursing homes, military barracks, group homes, correctional facilities, and similar institutional or shared housing. 4,780 residents live in group quarters (6.7% of population).
| Living in group quarters | 4,780 |
|---|
Other
| Congressional District · District | 3 |
|---|---|
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 29,183 |
| Cdc Birth Rate · State Fips | 29 |
| Cdc Birth Rate · County Fips | 183 |
| Cdc Birth Rate · County | St Charles |
| Cdc Birth Rate · Birth Rate | 7.0% |
| Cdc Birth Rate · Lower Ci | 6.30 |
| Cdc Birth Rate · Upper Ci | 7.80 |
| Cdc Mortality · Fips | 29,183 |
| Cdc Mortality · County | St. Charles County |
| Cdc Mortality · Urban Rural | Large fringe metro |
| Cdc Mortality · Total Deaths 2020 2023 | 11,643 |
| Cdc Vaccination · Fips | 29,183 |
| Cdc Vaccination · County | St. Charles County |
| Cdc Vaccination · Dose1 Pop Pct | 72.7% |
| Cdc Vaccination · Series Complete Pct | 64.3% |
| Cdc Vaccination · Booster Pct | 52.4% |
| Cdc Vaccination · Population 2019 | 402,022 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 3.50 |
| Family Score · Schools | 5 |
| Family Score · Children Pct | 17.7% |
| Family Score · Rating | fair |
| Town Summary · Key Facts | population 71,508, stable, family-oriented, upper-middle, white collar |
| Town Summary · Population | 71,508 people |
| Town Summary · County | St. Charles County |
Sources: NCES school congressional district assignment · federal dataset cascade