Crystal Lake, Illinois demographics

Crystal Lake, IL demographics: median age 39.3; 42.0% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Crystal Lake city, Illinois · Incorporated city · GEOID 1717887. The survey estimates a population of 40,579 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Crystal Lake is 39.3 years, with a 90% margin of error of 1.4 years. There are 14,806 households (±501). 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	39.3 ±1.4	39.0 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 40,579
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Under 18	9,493 ±801	23.4% ±2.0 pp	21.8%	22.0%
18–34	8,022 ±711	19.8% ±1.7 pp	22.7%	22.8%
35–64	17,011 ±921	41.9% ±2.3 pp	38.5%	38.0%
65 and older	6,053 ±535	14.9% ±1.3 pp	17.0%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 40,579
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Male	20,053 ±524	49.4% ±1.3 pp	49.4%	49.5%
Female	20,526 ±545	50.6% ±1.3 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: 40,579
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
White alone	32,878 ±953	81.0% ±2.3 pp	61.0%	61.0%
Black or African American alone	261 ±144 · low precision	0.6% ±0.4 pp · low precision	13.6%	12.2%
American Indian and Alaska Native alone	122 ±115 · low precision	0.3% ±0.3 pp · low precision	0.6%	0.9%
Asian alone	1,586 ±370	3.9% ±0.9 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	2,445 ±692	6.0% ±1.7 pp	7.9%	7.1%
Two or more races	3,287 ±759	8.1% ±1.9 pp	10.9%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 40,579
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Not Hispanic or Latino	34,979 ±803	86.2% ±1.9 pp	81.2%	80.7%
Hispanic or Latino	5,600 ±808	13.8% ±2.0 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: 14,806
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Married-couple family	8,422 ±388	56.9% ±1.8 pp	45.3%	46.9%
Other family: male householder, no spouse present	862 ±237	5.8% ±1.6 pp	4.9%	5.1%
Other family: female householder, no spouse present	1,394 ±267	9.4% ±1.8 pp	11.9%	12.2%
Nonfamily: householder living alone	3,051 ±449	20.6% ±3.0 pp	31.2%	28.7%
Nonfamily: householder not living alone	1,077 ±295	7.3% ±2.0 pp	6.7%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 14,806
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Households with people under 18	5,242 ±344	35.4% ±2.0 pp	28.6%	29.5%
Households without people under 18	9,564 ±717	64.6% ±4.3 pp	71.4%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 14,806
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
One-person nonfamily households	3,051 ±449	20.6% ±3.0 pp	31.2%	28.7%
Two-person households	5,257 ±579	35.5% ±3.7 pp	32.3%	33.8%
Three-person households	2,236 ±297	15.1% ±1.9 pp	14.7%	15.3%
Four-person households	2,607 ±345	17.6% ±2.3 pp	12.6%	12.6%
Five-person households	1,065 ±300	7.2% ±2.0 pp	5.8%	5.9%
Six-person households	451 ±222	3.0% ±1.5 pp	2.1%	2.2%
Seven or more people	139 ±104 · low precision	0.9% ±0.7 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: 40,579
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Native	36,354 ±665	89.6% ±1.6 pp	85.3%	85.9%
Foreign born	4,225 ±660	10.4% ±1.6 pp	14.7%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 38,851
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
English only	32,347 ±957	83.3% ±2.3 pp	76.0%	77.7%
Spanish	3,882 ±742	10.0% ±1.9 pp	14.0%	13.6%
French, Haitian, or Cajun	51 ±68 · low precision	0.1% ±0.2 pp · low precision	0.3%	0.7%
German or other West Germanic	210 ±134 · low precision	0.5% ±0.3 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	974 ±465	2.5% ±1.2 pp	2.5%	0.7%
Other Indo-European	664 ±259	1.7% ±0.7 pp	2.6%	2.0%
Korean	63 ±60 · low precision	0.2% ±0.2 pp · low precision	0.3%	0.3%
Chinese, including Mandarin and Cantonese	95 ±103 · low precision	0.2% ±0.3 pp · low precision	0.9%	1.1%
Vietnamese	182 ±222 · low precision	0.5% ±0.6 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	129 ±121 · low precision	0.3% ±0.3 pp · low precision	0.7%	0.6%
Other Asian and Pacific Island	114 ±82 · low precision	0.3% ±0.2 pp · low precision	1.0%	1.1%
Arabic	84 ±122 · low precision	0.2% ±0.3 pp · low precision	0.6%	0.5%
Other and unspecified	56 ±53 · 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: 27,245
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Less than high school graduate	1,814 ±407	6.7% ±1.5 pp	9.5%	10.4%
High school graduate or equivalency	6,390 ±749	23.5% ±2.7 pp	25.1%	26.0%
Some college, no degree	5,459 ±595	20.0% ±2.1 pp	19.2%	19.1%
Associate’s degree	2,149 ±336	7.9% ±1.2 pp	8.3%	8.8%
Bachelor’s degree	7,686 ±618	28.2% ±2.2 pp	22.6%	21.6%
Graduate or professional degree	3,747 ±438	13.8% ±1.6 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: 40,426
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Same house	36,862 ±583	91.2% ±1.3 pp	88.9%	87.7%
Moved within same county	1,453 ±433	3.6% ±1.1 pp	6.4%	6.3%
Moved from a different county in the same state	1,674 ±535	4.1% ±1.3 pp	2.4%	3.1%
Moved from a different state	384 ±188	0.9% ±0.5 pp	1.6%	2.3%
Moved from abroad	53 ±41 · 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

3.6% of Crystal Lake residents (±1.1 percentage points) had no health insurance coverage when surveyed, compared with 6.9% in Illinois and 8.4% nationally. 96.0% 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	Crystal Lake	Illinois	U.S.	Compared with Illinois
People without health insurance Civilian noninstitutionalized population	3.6% ±1.1 pp	6.9%	8.4%	Lower
Households with a broadband subscription Households	96.0% ±1.4 pp	90.8%	91.0%	Higher
Veterans Civilian population age 18 and older	3.6% ±0.9 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 Crystal Lake . 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 Crystal Lake housing and cost context or return to the city profile.