Lake Forest, Illinois demographics

Lake Forest, IL demographics: median age 46.1; 80.5% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Lake Forest city, Illinois · Incorporated city · GEOID 1741105. The survey estimates a population of 19,416 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Lake Forest is 46.1 years, with a 90% margin of error of 2.3 years. There are 6,900 households (±264). 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	46.1 ±2.3	39.0 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 19,416
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Under 18	3,735 ±408	19.2% ±2.0 pp	21.8%	22.0%
18–34	4,140 ±623	21.3% ±3.2 pp	22.7%	22.8%
35–64	6,357 ±463	32.7% ±2.2 pp	38.5%	38.0%
65 and older	5,184 ±481	26.7% ±2.4 pp	17.0%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 19,416
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Male	9,252 ±471	47.7% ±2.0 pp	49.4%	49.5%
Female	10,164 ±448	52.3% ±1.7 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: 19,416
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
White alone	15,969 ±959	82.2% ±4.3 pp	61.0%	61.0%
Black or African American alone	186 ±96 · low precision	1.0% ±0.5 pp · low precision	13.6%	12.2%
American Indian and Alaska Native alone	50 ±71 · low precision	0.3% ±0.4 pp · low precision	0.6%	0.9%
Asian alone	1,255 ±393	6.5% ±2.0 pp	6.0%	6.0%
Native Hawaiian and Other Pacific Islander alone	0 ±20 · low precision	0.0% ±0.1 pp · low precision	0.0%	0.2%
Some other race alone	295 ±232 · low precision	1.5% ±1.2 pp · low precision	7.9%	7.1%
Two or more races	1,661 ±489	8.6% ±2.5 pp	10.9%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 19,416
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Not Hispanic or Latino	18,234 ±679	93.9% ±2.2 pp	81.2%	80.7%
Hispanic or Latino	1,182 ±361	6.1% ±1.9 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: 6,900
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Married-couple family	4,661 ±327	67.6% ±4.0 pp	45.3%	46.9%
Other family: male householder, no spouse present	97 ±58 · low precision	1.4% ±0.8 pp · low precision	4.9%	5.1%
Other family: female householder, no spouse present	502 ±165	7.3% ±2.4 pp	11.9%	12.2%
Nonfamily: householder living alone	1,305 ±234	18.9% ±3.3 pp	31.2%	28.7%
Nonfamily: householder not living alone	335 ±292 · low precision	4.9% ±4.2 pp · low precision	6.7%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 6,900
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Households with people under 18	1,970 ±175	28.6% ±2.3 pp	28.6%	29.5%
Households without people under 18	4,930 ±350	71.4% ±4.3 pp	71.4%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 6,900
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
One-person nonfamily households	1,305 ±234	18.9% ±3.3 pp	31.2%	28.7%
Two-person households	2,889 ±410	41.9% ±5.7 pp	32.3%	33.8%
Three-person households	1,015 ±223	14.7% ±3.2 pp	14.7%	15.3%
Four-person households	1,236 ±241	17.9% ±3.4 pp	12.6%	12.6%
Five-person households	339 ±92	4.9% ±1.3 pp	5.8%	5.9%
Six-person households	69 ±47 · low precision	1.0% ±0.7 pp · low precision	2.1%	2.2%
Seven or more people	47 ±67 · low precision	0.7% ±1.0 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: 19,416
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Native	17,323 ±710	89.2% ±2.6 pp	85.3%	85.9%
Foreign born	2,093 ±365	10.8% ±1.9 pp	14.7%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 18,452
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
English only	16,059 ±877	87.0% ±3.7 pp	76.0%	77.7%
Spanish	836 ±303	4.5% ±1.6 pp	14.0%	13.6%
French, Haitian, or Cajun	142 ±99 · low precision	0.8% ±0.5 pp · low precision	0.3%	0.7%
German or other West Germanic	90 ±58 · low precision	0.5% ±0.3 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	159 ±106 · low precision	0.9% ±0.6 pp · low precision	2.5%	0.7%
Other Indo-European	525 ±207	2.8% ±1.1 pp	2.6%	2.0%
Korean	179 ±185 · low precision	1.0% ±1.0 pp · low precision	0.3%	0.3%
Chinese, including Mandarin and Cantonese	215 ±128 · low precision	1.2% ±0.7 pp · low precision	0.9%	1.1%
Vietnamese	40 ±37 · low precision	0.2% ±0.2 pp · low precision	0.2%	0.5%
Tagalog, including Filipino	17 ±26 · low precision	0.1% ±0.1 pp · low precision	0.7%	0.6%
Other Asian and Pacific Island	111 ±87 · low precision	0.6% ±0.5 pp · low precision	1.0%	1.1%
Arabic	39 ±45 · low precision	0.2% ±0.2 pp · low precision	0.6%	0.5%
Other and unspecified	40 ±49 · 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: 13,295
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Less than high school graduate	247 ±120	1.9% ±0.9 pp	9.5%	10.4%
High school graduate or equivalency	647 ±157	4.9% ±1.2 pp	25.1%	26.0%
Some college, no degree	1,231 ±261	9.3% ±1.9 pp	19.2%	19.1%
Associate’s degree	464 ±161	3.5% ±1.2 pp	8.3%	8.8%
Bachelor’s degree	5,135 ±466	38.6% ±3.2 pp	22.6%	21.6%
Graduate or professional degree	5,571 ±655	41.9% ±4.7 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: 19,340
Category	Count ± MOE	Share ± MOE (pp)	Illinois	U.S.
Same house	16,321 ±797	84.4% ±3.3 pp	88.9%	87.7%
Moved within same county	1,002 ±355	5.2% ±1.8 pp	6.4%	6.3%
Moved from a different county in the same state	1,027 ±625 · low precision	5.3% ±3.2 pp · low precision	2.4%	3.1%
Moved from a different state	638 ±216	3.3% ±1.1 pp	1.6%	2.3%
Moved from abroad	352 ±195 · low precision	1.8% ±1.0 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

1.8% of Lake Forest residents (±0.7 percentage points) had no health insurance coverage when surveyed, compared with 6.9% in Illinois and 8.4% nationally. 95.4% 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	Lake Forest	Illinois	U.S.	Compared with Illinois
People without health insurance Civilian noninstitutionalized population	1.8% ±0.7 pp	6.9%	8.4%	Lower
Households with a broadband subscription Households	95.4% ±1.6 pp	90.8%	91.0%	Higher
Veterans Civilian population age 18 and older	2.7% ±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 Lake Forest . 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 Lake Forest housing and cost context or return to the city profile.