Round Lake, Illinois demographics

Round Lake, IL demographics: median age 36.1; 41.5% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Round Lake village, Illinois · Incorporated village · GEOID 1766027. The survey estimates a population of 18,628 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Round Lake is 36.1 years, with a 90% margin of error of 2.3 years. There are 6,430 households (±429). 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	36.1 ±2.3	39.0 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 18,628
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Under 18	5,252 ±627	28.2% ±3.4 pp	21.8%	22.0%
18–34	3,707 ±537	19.9% ±2.9 pp	22.7%	22.8%
35–64	8,007 ±813	43.0% ±4.4 pp	38.5%	38.0%
65 and older	1,662 ±433	8.9% ±2.3 pp	17.0%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 18,628
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Male	9,026 ±498	48.5% ±2.7 pp	49.4%	49.5%
Female	9,602 ±502	51.5% ±2.7 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: 18,628
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
White alone	9,261 ±996	49.7% ±5.3 pp	61.0%	61.0%
Black or African American alone	763 ±299	4.1% ±1.6 pp	13.6%	12.2%
American Indian and Alaska Native alone	225 ±279 · low precision	1.2% ±1.5 pp · low precision	0.6%	0.9%
Asian alone	2,282 ±627	12.3% ±3.4 pp	6.0%	6.0%
Native Hawaiian and Other Pacific Islander alone	25 ±36 · low precision	0.1% ±0.2 pp · low precision	0.0%	0.2%
Some other race alone	1,827 ±607	9.8% ±3.3 pp	7.9%	7.1%
Two or more races	4,245 ±939	22.8% ±5.0 pp	10.9%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 18,628
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Not Hispanic or Latino	11,951 ±862	64.2% ±4.6 pp	81.2%	80.7%
Hispanic or Latino	6,677 ±859	35.8% ±4.6 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: 6,430
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Married-couple family	3,676 ±389	57.2% ±4.7 pp	45.3%	46.9%
Other family: male householder, no spouse present	268 ±155 · low precision	4.2% ±2.4 pp · low precision	4.9%	5.1%
Other family: female householder, no spouse present	561 ±188	8.7% ±2.9 pp	11.9%	12.2%
Nonfamily: householder living alone	1,502 ±483	23.4% ±7.3 pp	31.2%	28.7%
Nonfamily: householder not living alone	423 ±276 · low precision	6.6% ±4.3 pp · low precision	6.7%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 6,430
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Households with people under 18	2,541 ±224	39.5% ±2.3 pp	28.6%	29.5%
Households without people under 18	3,889 ±548	60.5% ±7.5 pp	71.4%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 6,430
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
One-person nonfamily households	1,502 ±483	23.4% ±7.3 pp	31.2%	28.7%
Two-person households	1,583 ±418	24.6% ±6.3 pp	32.3%	33.8%
Three-person households	1,212 ±335	18.8% ±5.1 pp	14.7%	15.3%
Four-person households	1,256 ±260	19.5% ±3.8 pp	12.6%	12.6%
Five-person households	566 ±168	8.8% ±2.5 pp	5.8%	5.9%
Six-person households	185 ±117 · low precision	2.9% ±1.8 pp · low precision	2.1%	2.2%
Seven or more people	126 ±81 · low precision	2.0% ±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: 18,628
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Native	14,041 ±780	75.4% ±4.2 pp	85.3%	85.9%
Foreign born	4,587 ±785	24.6% ±4.2 pp	14.7%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 17,471
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
English only	10,089 ±995	57.7% ±5.6 pp	76.0%	77.7%
Spanish	4,651 ±833	26.6% ±4.7 pp	14.0%	13.6%
French, Haitian, or Cajun	0 ±20 · low precision	0.0% ±0.1 pp · low precision	0.3%	0.7%
German or other West Germanic	34 ±38 · low precision	0.2% ±0.2 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	666 ±380 · low precision	3.8% ±2.2 pp · low precision	2.5%	0.7%
Other Indo-European	587 ±331 · low precision	3.4% ±1.9 pp · low precision	2.6%	2.0%
Korean	44 ±54 · low precision	0.3% ±0.3 pp · low precision	0.3%	0.3%
Chinese, including Mandarin and Cantonese	107 ±173 · low precision	0.6% ±1.0 pp · low precision	0.9%	1.1%
Vietnamese	85 ±84 · low precision	0.5% ±0.5 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	402 ±268 · low precision	2.3% ±1.5 pp · low precision	0.7%	0.6%
Other Asian and Pacific Island	614 ±483 · low precision	3.5% ±2.8 pp · low precision	1.0%	1.1%
Arabic	156 ±173 · low precision	0.9% ±1.0 pp · low precision	0.6%	0.5%
Other and unspecified	36 ±52 · low precision	0.2% ±0.3 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: 11,996
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Less than high school graduate	1,464 ±409	12.2% ±3.4 pp	9.5%	10.4%
High school graduate or equivalency	2,659 ±473	22.2% ±3.8 pp	25.1%	26.0%
Some college, no degree	2,012 ±434	16.8% ±3.5 pp	19.2%	19.1%
Associate’s degree	880 ±274	7.3% ±2.3 pp	8.3%	8.8%
Bachelor’s degree	3,780 ±627	31.5% ±5.0 pp	22.6%	21.6%
Graduate or professional degree	1,201 ±359	10.0% ±3.0 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: 18,385
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Same house	16,940 ±510	92.1% ±2.7 pp	88.9%	87.7%
Moved within same county	676 ±366 · low precision	3.7% ±2.0 pp · low precision	6.4%	6.3%
Moved from a different county in the same state	208 ±136 · low precision	1.1% ±0.7 pp · low precision	2.4%	3.1%
Moved from a different state	545 ±370 · low precision	3.0% ±2.0 pp · low precision	1.6%	2.3%
Moved from abroad	16 ±20 · 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 Round Lake residents (±1.4 percentage points) had no health insurance coverage when surveyed, compared with 6.9% in Illinois and 8.4% nationally. 98.1% 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	Round Lake	Illinois	U.S.	Compared with Illinois
People without health insurance Civilian noninstitutionalized population	4.2% ±1.4 pp	6.9%	8.4%	Lower
Households with a broadband subscription Households	98.1% ±1.8 pp	90.8%	91.0%	Higher
Veterans Civilian population age 18 and older	2.0% ±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 Round 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 Round Lake housing and cost context or return to the city profile.