Waterloo, Illinois demographics

Waterloo, IL demographics: median age 41.5; 37.3% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Waterloo city, Illinois · Incorporated city · GEOID 1779150. The survey estimates a population of 11,129 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Waterloo is 41.5 years, with a 90% margin of error of 2.6 years. There are 4,491 households (±227). 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 ±2.6	39.0 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 11,129
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Under 18	2,438 ±308	21.9% ±2.8 pp	21.8%	22.0%
18–34	2,003 ±325	18.0% ±2.9 pp	22.7%	22.8%
35–64	4,395 ±471	39.5% ±4.2 pp	38.5%	38.0%
65 and older	2,293 ±353	20.6% ±3.2 pp	17.0%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 11,129
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Male	5,436 ±214	48.8% ±1.9 pp	49.4%	49.5%
Female	5,693 ±214	51.2% ±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: 11,129
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
White alone	10,503 ±214	94.4% ±1.9 pp	61.0%	61.0%
Black or African American alone	115 ±63 · low precision	1.0% ±0.6 pp · low precision	13.6%	12.2%
American Indian and Alaska Native alone	15 ±20 · low precision	0.1% ±0.2 pp · low precision	0.6%	0.9%
Asian alone	189 ±71	1.7% ±0.6 pp	6.0%	6.0%
Native Hawaiian and Other Pacific Islander alone	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.0%	0.2%
Some other race alone	49 ±65 · low precision	0.4% ±0.6 pp · low precision	7.9%	7.1%
Two or more races	258 ±165 · low precision	2.3% ±1.5 pp · low precision	10.9%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 11,129
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Not Hispanic or Latino	10,929 ±170	98.2% ±1.5 pp	81.2%	80.7%
Hispanic or Latino	200 ±165 · low precision	1.8% ±1.5 pp · low precision	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: 4,491
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Married-couple family	2,463 ±196	54.8% ±3.4 pp	45.3%	46.9%
Other family: male householder, no spouse present	216 ±113 · low precision	4.8% ±2.5 pp · low precision	4.9%	5.1%
Other family: female householder, no spouse present	376 ±144	8.4% ±3.2 pp	11.9%	12.2%
Nonfamily: householder living alone	1,235 ±250	27.5% ±5.4 pp	31.2%	28.7%
Nonfamily: householder not living alone	201 ±99	4.5% ±2.2 pp	6.7%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 4,491
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Households with people under 18	1,474 ±165	32.8% ±3.3 pp	28.6%	29.5%
Households without people under 18	3,017 ±297	67.2% ±5.7 pp	71.4%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 4,491
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
One-person nonfamily households	1,235 ±250	27.5% ±5.4 pp	31.2%	28.7%
Two-person households	1,392 ±230	31.0% ±4.9 pp	32.3%	33.8%
Three-person households	896 ±190	20.0% ±4.1 pp	14.7%	15.3%
Four-person households	700 ±180	15.6% ±3.9 pp	12.6%	12.6%
Five-person households	175 ±87	3.9% ±1.9 pp	5.8%	5.9%
Six-person households	62 ±57 · low precision	1.4% ±1.3 pp · low precision	2.1%	2.2%
Seven or more people	31 ±51 · low precision	0.7% ±1.1 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: 11,129
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Native	10,832 ±129	97.3% ±1.1 pp	85.3%	85.9%
Foreign born	297 ±125	2.7% ±1.1 pp	14.7%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 10,518
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
English only	10,246 ±215	97.4% ±1.4 pp	76.0%	77.7%
Spanish	144 ±114 · low precision	1.4% ±1.1 pp · low precision	14.0%	13.6%
French, Haitian, or Cajun	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.3%	0.7%
German or other West Germanic	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	0 ±20 · low precision	0.0% ±0.2 pp · low precision	2.5%	0.7%
Other Indo-European	0 ±20 · low precision	0.0% ±0.2 pp · low precision	2.6%	2.0%
Korean	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.3%	0.3%
Chinese, including Mandarin and Cantonese	74 ±72 · low precision	0.7% ±0.7 pp · low precision	0.9%	1.1%
Vietnamese	18 ±25 · low precision	0.2% ±0.2 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	10 ±16 · low precision	0.1% ±0.2 pp · low precision	0.7%	0.6%
Other Asian and Pacific Island	26 ±40 · low precision	0.2% ±0.4 pp · low precision	1.0%	1.1%
Arabic	0 ±20 · low precision	0.0% ±0.2 pp · low precision	0.6%	0.5%
Other and unspecified	0 ±20 · low precision	0.0% ±0.2 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: 7,879
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Less than high school graduate	259 ±136 · low precision	3.3% ±1.7 pp · low precision	9.5%	10.4%
High school graduate or equivalency	1,814 ±295	23.0% ±3.7 pp	25.1%	26.0%
Some college, no degree	2,121 ±370	26.9% ±4.6 pp	19.2%	19.1%
Associate’s degree	746 ±205	9.5% ±2.6 pp	8.3%	8.8%
Bachelor’s degree	1,852 ±281	23.5% ±3.5 pp	22.6%	21.6%
Graduate or professional degree	1,087 ±226	13.8% ±2.8 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: 11,096
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Same house	10,112 ±260	91.1% ±2.3 pp	88.9%	87.7%
Moved within same county	613 ±221	5.5% ±2.0 pp	6.4%	6.3%
Moved from a different county in the same state	236 ±119 · low precision	2.1% ±1.1 pp · low precision	2.4%	3.1%
Moved from a different state	119 ±99 · low precision	1.1% ±0.9 pp · low precision	1.6%	2.3%
Moved from abroad	16 ±20 · 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

3.4% of Waterloo residents (±1.4 percentage points) had no health insurance coverage when surveyed, compared with 6.9% in Illinois and 8.4% nationally. 94.6% 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	Waterloo	Illinois	U.S.	Compared with Illinois
People without health insurance Civilian noninstitutionalized population	3.4% ±1.4 pp	6.9%	8.4%	Lower
Households with a broadband subscription Households	94.6% ±1.8 pp	90.8%	91.0%	Higher
Veterans Civilian population age 18 and older	8.8% ±2.7 pp	4.8%	6.2%	Higher

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 Waterloo . 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 Waterloo housing and cost context or return to the city profile.