Lake St. Louis, Missouri demographics

Lake St. Louis, MO demographics: median age 42.7; 51.7% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Lake St. Louis city, Missouri · Incorporated city · GEOID 2940043. The survey estimates a population of 18,066 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Lake St. Louis is 42.7 years, with a 90% margin of error of 2.7 years. There are 7,351 households (±317). Age and household distributions show how these totals are composed; they do not establish which neighborhood suits a particular person.

Every count and share is an estimate. “±” is a 90% margin of error (MOE); pp means percentage points. Derived shares use the category count divided by the named universe. Aggregated category MOEs and percentage MOEs are approximate. A margin larger than half its estimate is flagged as low precision. Blank source uncertainty is shown as unavailable, never zero.

Age distribution and sex

City, state and U.S. estimates · ACS 2020–2024
Measure / survey universe	City estimate ± MOE	State estimate ± MOE	U.S. estimate ± MOE
Median age Total population · years	42.7 ±2.7	39.0 ±0.2	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 18,066
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Under 18	3,624 ±492	20.1% ±2.7 pp	22.3%	22.0%
18–34	3,516 ±502	19.5% ±2.8 pp	22.3%	22.8%
35–64	7,214 ±631	39.9% ±3.5 pp	37.5%	38.0%
65 and older	3,712 ±400	20.5% ±2.2 pp	17.9%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 18,066
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Male	9,131 ±438	50.5% ±2.4 pp	49.3%	49.5%
Female	8,935 ±432	49.5% ±2.4 pp	50.7%	50.5%

The age groups are mutually exclusive and cover the entire population. The sex categories follow this ACS table’s published classification; they are not a survey of gender identity.

Race and Hispanic origin

Race · B02001 · ACS 2020–2024 Total population: 18,066
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
White alone	15,427 ±627	85.4% ±3.5 pp	77.5%	61.0%
Black or African American alone	999 ±421	5.5% ±2.3 pp	11.0%	12.2%
American Indian and Alaska Native alone	23 ±27 · low precision	0.1% ±0.1 pp · low precision	0.3%	0.9%
Asian alone	343 ±203 · low precision	1.9% ±1.1 pp · low precision	2.1%	6.0%
Native Hawaiian and Other Pacific Islander alone	0 ±19 · low precision	0.0% ±0.1 pp · low precision	0.1%	0.2%
Some other race alone	170 ±123 · low precision	0.9% ±0.7 pp · low precision	1.9%	7.1%
Two or more races	1,104 ±359	6.1% ±2.0 pp	7.1%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 18,066
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Not Hispanic or Latino	17,613 ±210	97.5% ±1.1 pp	94.8%	80.7%
Hispanic or Latino	453 ±206	2.5% ±1.1 pp	5.2%	19.3%

Hispanic origin and race are separate questions. People of Hispanic or Latino origin may be of any race and appear in both tables. Do not add the Hispanic share to race shares. Race alone and two-or-more-race groups are the mutually exclusive categories of the race table.

Household types, children and living alone

Household types · B11001 · ACS 2020–2024 Households: 7,351
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Married-couple family	4,730 ±275	64.3% ±2.5 pp	46.5%	46.9%
Other family: male householder, no spouse present	265 ±119	3.6% ±1.6 pp	4.6%	5.1%
Other family: female householder, no spouse present	344 ±119	4.7% ±1.6 pp	11.0%	12.2%
Nonfamily: householder living alone	1,491 ±334	20.3% ±4.5 pp	31.1%	28.7%
Nonfamily: householder not living alone	521 ±226	7.1% ±3.1 pp	6.7%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 7,351
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Households with people under 18	2,085 ±247	28.4% ±3.1 pp	28.5%	29.5%
Households without people under 18	5,266 ±478	71.6% ±5.7 pp	71.5%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 7,351
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
One-person nonfamily households	1,491 ±334	20.3% ±4.5 pp	31.1%	28.7%
Two-person households	3,172 ±391	43.2% ±5.0 pp	35.0%	33.8%
Three-person households	1,018 ±189	13.8% ±2.5 pp	14.1%	15.3%
Four-person households	1,092 ±260	14.9% ±3.5 pp	11.6%	12.6%
Five-person households	373 ±118	5.1% ±1.6 pp	5.2%	5.9%
Six-person households	125 ±74 · low precision	1.7% ±1.0 pp · low precision	1.9%	2.2%
Seven or more people	80 ±62 · low precision	1.1% ±0.8 pp · low precision	1.1%	1.4%

A family household contains related people under the Census definition. A nonfamily household can contain one person or unrelated people sharing a home. Households with children can also appear in the household-type and size tables, so those tables must not be added together. Household estimates exclude people living in group quarters from the household universe.

Nativity and languages spoken at home

Nativity · B05002 · ACS 2020–2024 Total population: 18,066
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Native	17,344 ±231	96.0% ±1.3 pp	95.5%	85.9%
Foreign born	722 ±229	4.0% ±1.3 pp	4.5%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 17,494
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
English only	16,694 ±282	95.4% ±1.3 pp	93.3%	77.7%
Spanish	240 ±102	1.4% ±0.6 pp	2.9%	13.6%
French, Haitian, or Cajun	10 ±17 · low precision	0.1% ±0.1 pp · low precision	0.3%	0.7%
German or other West Germanic	74 ±86 · low precision	0.4% ±0.5 pp · low precision	0.5%	0.5%
Russian, Polish, or other Slavic	51 ±53 · low precision	0.3% ±0.3 pp · low precision	0.5%	0.7%
Other Indo-European	229 ±155 · low precision	1.3% ±0.9 pp · low precision	0.6%	2.0%
Korean	27 ±34 · low precision	0.2% ±0.2 pp · low precision	0.1%	0.3%
Chinese, including Mandarin and Cantonese	23 ±37 · low precision	0.1% ±0.2 pp · low precision	0.4%	1.1%
Vietnamese	0 ±19 · low precision	0.0% ±0.1 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	26 ±29 · low precision	0.1% ±0.2 pp · low precision	0.2%	0.6%
Other Asian and Pacific Island	0 ±19 · low precision	0.0% ±0.1 pp · low precision	0.5%	1.1%
Arabic	95 ±111 · low precision	0.5% ±0.6 pp · low precision	0.2%	0.5%
Other and unspecified	25 ±38 · low precision	0.1% ±0.2 pp · low precision	0.4%	0.8%

Foreign born means not a U.S. citizen at birth; it includes naturalized citizens. Language categories describe speech at home among people age five and older. A language other than English at home does not establish that someone cannot speak English. This city page uses the published C16001 summary categories because the more detailed B16001 table does not provide these city records in this release.

Educational attainment

Highest completed education · B15003 · ACS 2020–2024 Population age 25 and older: 12,473
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Less than high school graduate	368 ±221 · low precision	3.0% ±1.8 pp · low precision	8.1%	10.4%
High school graduate or equivalency	1,874 ±319	15.0% ±2.5 pp	30.2%	26.0%
Some college, no degree	2,828 ±472	22.7% ±3.7 pp	20.8%	19.1%
Associate’s degree	952 ±217	7.6% ±1.7 pp	8.4%	8.8%
Bachelor’s degree	4,261 ±449	34.2% ±3.5 pp	19.8%	21.6%
Graduate or professional degree	2,190 ±311	17.6% ±2.4 pp	12.6%	14.1%

The denominator excludes residents under 25. Each person is counted in the highest attainment category they completed. This table does not measure the quality of local schools or the education level of every current student.

Residence one year earlier

Geographic mobility · B07003 · ACS 2020–2024 Population age 1 and older: 18,002
Category	Count ± MOE	Share ± MOE (pp)	Missouri	U.S.
Same house	15,302 ±606	85.0% ±3.4 pp	87.4%	87.7%
Moved within same county	1,262 ±467	7.0% ±2.6 pp	6.2%	6.3%
Moved from a different county in the same state	827 ±320	4.6% ±1.8 pp	3.6%	3.1%
Moved from a different state	476 ±201	2.6% ±1.1 pp	2.5%	2.3%
Moved from abroad	135 ±126 · low precision	0.7% ±0.7 pp · low precision	0.4%	0.6%

These are respondents’ residence patterns one year before their survey response, pooled across the five-year window. They are not a net migration count for 2025. A person can move to a different house within the same city or county; moves within the same county should not automatically be interpreted as new arrivals to the city.

Health insurance, internet access and veterans

3.5% of Lake St. Louis residents (±1.3 percentage points) had no health insurance coverage when surveyed, compared with 8.8% in Missouri and 8.4% nationally. 98.3% of households subscribe to broadband of any type, including cellular data plans. A subscription is not the same as available service: the FCC National Broadband Map shows providers at a specific address.

City, state and U.S. shares · ACS 2020–2024
Measure	Lake St. Louis	Missouri	U.S.	Compared with Missouri
People without health insurance Civilian noninstitutionalized population	3.5% ±1.3 pp	8.8%	8.4%	Lower
Households with a broadband subscription Households	98.3% ±0.2 pp	89.3%	91.0%	Higher
Veterans Civilian population age 18 and older	8.7% ±1.8 pp	7.3%	6.2%	Not statistically different

Reading and reusing the estimates

The Census table links above lead to the original detailed tables. Counts, source universes and uncertainty are retained in the source observation download for Lake St. Louis . Compare these figures with the same survey window; do not compare one city’s five-year estimate with another city’s annual estimate as though they measured the same period. For methods, see uncertainty and denominator calculations.

Read Lake St. Louis housing and cost context or return to the city profile.