Eureka, Illinois demographics

Eureka, IL demographics: median age 42.2; 32.2% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Eureka city, Illinois · Incorporated city · GEOID 1724543. The survey estimates a population of 5,007 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Eureka is 42.2 years, with a 90% margin of error of 11.9 years. There are 2,199 households (±252). 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	42.2 ±11.9	39.0 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 5,007
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Under 18	938 ±253	18.7% ±4.7 pp	21.8%	22.0%
18–34	1,079 ±240	21.5% ±4.3 pp	22.7%	22.8%
35–64	1,768 ±338	35.3% ±5.7 pp	38.5%	38.0%
65 and older	1,222 ±265	24.4% ±4.7 pp	17.0%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 5,007
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Male	2,268 ±354	45.3% ±5.4 pp	49.4%	49.5%
Female	2,739 ±319	54.7% ±3.1 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: 5,007
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
White alone	4,672 ±518	93.3% ±4.1 pp	61.0%	61.0%
Black or African American alone	89 ±48 · low precision	1.8% ±0.9 pp · low precision	13.6%	12.2%
American Indian and Alaska Native alone	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.6%	0.9%
Asian alone	24 ±22 · low precision	0.5% ±0.4 pp · low precision	6.0%	6.0%
Native Hawaiian and Other Pacific Islander alone	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.0%	0.2%
Some other race alone	89 ±80 · low precision	1.8% ±1.6 pp · low precision	7.9%	7.1%
Two or more races	133 ±107 · low precision	2.7% ±2.1 pp · low precision	10.9%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 5,007
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Not Hispanic or Latino	4,869 ±504	97.2% ±1.8 pp	81.2%	80.7%
Hispanic or Latino	138 ±66	2.8% ±1.3 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: 2,199
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Married-couple family	906 ±169	41.2% ±6.1 pp	45.3%	46.9%
Other family: male householder, no spouse present	47 ±57 · low precision	2.1% ±2.6 pp · low precision	4.9%	5.1%
Other family: female householder, no spouse present	153 ±95 · low precision	7.0% ±4.2 pp · low precision	11.9%	12.2%
Nonfamily: householder living alone	1,078 ±270	49.0% ±10.9 pp	31.2%	28.7%
Nonfamily: householder not living alone	15 ±27 · low precision	0.7% ±1.2 pp · low precision	6.7%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 2,199
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Households with people under 18	437 ±124	19.9% ±5.2 pp	28.6%	29.5%
Households without people under 18	1,762 ±288	80.1% ±9.3 pp	71.4%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 2,199
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
One-person nonfamily households	1,078 ±270	49.0% ±10.9 pp	31.2%	28.7%
Two-person households	571 ±118	26.0% ±4.5 pp	32.3%	33.8%
Three-person households	252 ±117	11.5% ±5.2 pp	14.7%	15.3%
Four-person households	140 ±88 · low precision	6.4% ±3.9 pp · low precision	12.6%	12.6%
Five-person households	82 ±71 · low precision	3.7% ±3.2 pp · low precision	5.8%	5.9%
Six-person households	76 ±66 · low precision	3.5% ±3.0 pp · low precision	2.1%	2.2%
Seven or more people	0 ±25 · low precision	0.0% ±1.2 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: 5,007
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Native	4,982 ±510	99.5% ±1.0 pp	85.3%	85.9%
Foreign born	25 ±28 · low precision	0.5% ±0.6 pp · low precision	14.7%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 4,761
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
English only	4,648 ±496	97.6% ±1.5 pp	76.0%	77.7%
Spanish	80 ±56 · low precision	1.7% ±1.2 pp · low precision	14.0%	13.6%
French, Haitian, or Cajun	20 ±21 · low precision	0.4% ±0.4 pp · low precision	0.3%	0.7%
German or other West Germanic	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	0 ±18 · low precision	0.0% ±0.4 pp · low precision	2.5%	0.7%
Other Indo-European	3 ±8 · low precision	0.1% ±0.2 pp · low precision	2.6%	2.0%
Korean	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.3%	0.3%
Chinese, including Mandarin and Cantonese	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.9%	1.1%
Vietnamese	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.7%	0.6%
Other Asian and Pacific Island	1 ±4 · low precision	0.0% ±0.1 pp · low precision	1.0%	1.1%
Arabic	0 ±18 · low precision	0.0% ±0.4 pp · low precision	0.6%	0.5%
Other and unspecified	9 ±19 · low precision	0.2% ±0.4 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: 3,355
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Less than high school graduate	108 ±111 · low precision	3.2% ±3.3 pp · low precision	9.5%	10.4%
High school graduate or equivalency	856 ±269	25.5% ±7.4 pp	25.1%	26.0%
Some college, no degree	838 ±253	25.0% ±6.9 pp	19.2%	19.1%
Associate’s degree	473 ±206	14.1% ±5.9 pp	8.3%	8.8%
Bachelor’s degree	740 ±222	22.1% ±6.1 pp	22.6%	21.6%
Graduate or professional degree	340 ±134	10.1% ±3.8 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: 4,932
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Same house	4,213 ±541	85.4% ±6.5 pp	88.9%	87.7%
Moved within same county	411 ±254 · low precision	8.3% ±5.1 pp · low precision	6.4%	6.3%
Moved from a different county in the same state	277 ±145 · low precision	5.6% ±2.9 pp · low precision	2.4%	3.1%
Moved from a different state	27 ±30 · low precision	0.5% ±0.6 pp · low precision	1.6%	2.3%
Moved from abroad	4 ±9 · low precision	0.1% ±0.2 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

6.2% of Eureka residents (±3.5 percentage points) had no health insurance coverage when surveyed, compared with 6.9% in Illinois and 8.4% nationally. 83.7% 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	Eureka	Illinois	U.S.	Compared with Illinois
People without health insurance Civilian noninstitutionalized population	6.2% ±3.5 pp · low precision	6.9%	8.4%	Not statistically different
Households with a broadband subscription Households	83.7% ±9.0 pp	90.8%	91.0%	Not statistically different
Veterans Civilian population age 18 and older	2.4% ±1.6 pp · low precision	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 Eureka . 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 Eureka housing and cost context or return to the city profile.