St. Charles, Illinois demographics

St. Charles, IL demographics: median age 41.5; 52.0% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · St. Charles city, Illinois · Incorporated city · GEOID 1766703. The survey estimates a population of 32,854 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in St. Charles is 41.5 years, with a 90% margin of error of 1.7 years. There are 13,161 households (±421). 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	41.5 ±1.7	39.0 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 32,854
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Under 18	6,609 ±623	20.1% ±1.9 pp	21.8%	22.0%
18–34	7,170 ±796	21.8% ±2.4 pp	22.7%	22.8%
35–64	13,354 ±849	40.6% ±2.6 pp	38.5%	38.0%
65 and older	5,721 ±507	17.4% ±1.5 pp	17.0%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 32,854
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Male	16,577 ±640	50.5% ±1.9 pp	49.4%	49.5%
Female	16,277 ±640	49.5% ±1.9 pp	50.6%	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: 32,854
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
White alone	25,613 ±993	78.0% ±3.0 pp	61.0%	61.0%
Black or African American alone	944 ±486 · low precision	2.9% ±1.5 pp · low precision	13.6%	12.2%
American Indian and Alaska Native alone	349 ±258 · low precision	1.1% ±0.8 pp · low precision	0.6%	0.9%
Asian alone	1,633 ±511	5.0% ±1.6 pp	6.0%	6.0%
Native Hawaiian and Other Pacific Islander alone	0 ±27 · low precision	0.0% ±0.1 pp · low precision	0.0%	0.2%
Some other race alone	1,055 ±743 · low precision	3.2% ±2.3 pp · low precision	7.9%	7.1%
Two or more races	3,260 ±763	9.9% ±2.3 pp	10.9%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 32,854
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Not Hispanic or Latino	28,807 ±895	87.7% ±2.7 pp	81.2%	80.7%
Hispanic or Latino	4,047 ±861	12.3% ±2.6 pp	18.8%	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: 13,161
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Married-couple family	6,978 ±448	53.0% ±3.0 pp	45.3%	46.9%
Other family: male householder, no spouse present	634 ±214	4.8% ±1.6 pp	4.9%	5.1%
Other family: female householder, no spouse present	1,211 ±327	9.2% ±2.5 pp	11.9%	12.2%
Nonfamily: householder living alone	3,251 ±394	24.7% ±2.9 pp	31.2%	28.7%
Nonfamily: householder not living alone	1,087 ±282	8.3% ±2.1 pp	6.7%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 13,161
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Households with people under 18	3,874 ±330	29.4% ±2.3 pp	28.6%	29.5%
Households without people under 18	9,287 ±522	70.6% ±3.3 pp	71.4%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 13,161
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
One-person nonfamily households	3,251 ±394	24.7% ±2.9 pp	31.2%	28.7%
Two-person households	4,855 ±532	36.9% ±3.9 pp	32.3%	33.8%
Three-person households	2,676 ±416	20.3% ±3.1 pp	14.7%	15.3%
Four-person households	1,358 ±235	10.3% ±1.8 pp	12.6%	12.6%
Five-person households	665 ±187	5.1% ±1.4 pp	5.8%	5.9%
Six-person households	197 ±133 · low precision	1.5% ±1.0 pp · low precision	2.1%	2.2%
Seven or more people	159 ±112 · low precision	1.2% ±0.9 pp · low precision	1.3%	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: 32,854
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Native	29,448 ±719	89.6% ±2.1 pp	85.3%	85.9%
Foreign born	3,406 ±671	10.4% ±2.0 pp	14.7%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 31,615
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
English only	26,020 ±1,076	82.3% ±3.3 pp	76.0%	77.7%
Spanish	3,047 ±918	9.6% ±2.9 pp	14.0%	13.6%
French, Haitian, or Cajun	0 ±27 · low precision	0.0% ±0.1 pp · low precision	0.3%	0.7%
German or other West Germanic	97 ±69 · low precision	0.3% ±0.2 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	805 ±499 · low precision	2.5% ±1.6 pp · low precision	2.5%	0.7%
Other Indo-European	886 ±335	2.8% ±1.1 pp	2.6%	2.0%
Korean	40 ±53 · low precision	0.1% ±0.2 pp · low precision	0.3%	0.3%
Chinese, including Mandarin and Cantonese	93 ±81 · low precision	0.3% ±0.3 pp · low precision	0.9%	1.1%
Vietnamese	0 ±27 · low precision	0.0% ±0.1 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	164 ±137 · low precision	0.5% ±0.4 pp · low precision	0.7%	0.6%
Other Asian and Pacific Island	428 ±349 · low precision	1.4% ±1.1 pp · low precision	1.0%	1.1%
Arabic	0 ±27 · low precision	0.0% ±0.1 pp · low precision	0.6%	0.5%
Other and unspecified	35 ±35 · low precision	0.1% ±0.1 pp · low precision	0.6%	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: 23,236
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Less than high school graduate	1,393 ±395	6.0% ±1.7 pp	9.5%	10.4%
High school graduate or equivalency	3,760 ±497	16.2% ±2.1 pp	25.1%	26.0%
Some college, no degree	4,269 ±569	18.4% ±2.4 pp	19.2%	19.1%
Associate’s degree	1,731 ±340	7.4% ±1.4 pp	8.3%	8.8%
Bachelor’s degree	7,352 ±655	31.6% ±2.7 pp	22.6%	21.6%
Graduate or professional degree	4,731 ±541	20.4% ±2.3 pp	15.3%	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: 32,641
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Same house	27,676 ±961	84.8% ±2.9 pp	88.9%	87.7%
Moved within same county	2,631 ±662	8.1% ±2.0 pp	6.4%	6.3%
Moved from a different county in the same state	1,999 ±582	6.1% ±1.8 pp	2.4%	3.1%
Moved from a different state	312 ±221 · low precision	1.0% ±0.7 pp · low precision	1.6%	2.3%
Moved from abroad	23 ±30 · low precision	0.1% ±0.1 pp · low precision	0.6%	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

4.2% of St. Charles residents (±1.2 percentage points) had no health insurance coverage when surveyed, compared with 6.9% in Illinois and 8.4% nationally. 95.0% 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	St. Charles	Illinois	U.S.	Compared with Illinois
People without health insurance Civilian noninstitutionalized population	4.2% ±1.2 pp	6.9%	8.4%	Lower
Households with a broadband subscription Households	95.0% ±1.2 pp	90.8%	91.0%	Higher
Veterans Civilian population age 18 and older	4.0% ±0.7 pp	4.8%	6.2%	Lower

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 St. Charles . 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 St. Charles housing and cost context or return to the city profile.