Montclair, California demographics

Montclair, CA demographics: median age 33.7; 18.8% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Montclair city, California · Incorporated city · GEOID 0648788. The survey estimates a population of 37,810 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Montclair is 33.7 years, with a 90% margin of error of 1.7 years. There are 10,652 households (±485). 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	33.7 ±1.7	37.9 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 37,810
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Under 18	8,879 ±883	23.5% ±2.3 pp	22.0%	22.0%
18–34	11,028 ±950	29.2% ±2.5 pp	23.9%	22.8%
35–64	13,334 ±843	35.3% ±2.2 pp	38.5%	38.0%
65 and older	4,569 ±459	12.1% ±1.2 pp	15.7%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 37,810
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Male	18,537 ±853	49.0% ±2.3 pp	49.9%	49.5%
Female	19,273 ±854	51.0% ±2.3 pp	50.1%	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: 37,810
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
White alone	8,027 ±1,253	21.2% ±3.3 pp	39.7%	61.0%
Black or African American alone	2,448 ±1,062	6.5% ±2.8 pp	5.4%	12.2%
American Indian and Alaska Native alone	1,016 ±494	2.7% ±1.3 pp	1.3%	0.9%
Asian alone	3,962 ±760	10.5% ±2.0 pp	15.5%	6.0%
Native Hawaiian and Other Pacific Islander alone	32 ±57 · low precision	0.1% ±0.2 pp · low precision	0.4%	0.2%
Some other race alone	12,817 ±1,283	33.9% ±3.4 pp	18.5%	7.1%
Two or more races	9,508 ±1,750	25.1% ±4.6 pp	19.2%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 37,810
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Not Hispanic or Latino	10,399 ±1,263	27.5% ±3.3 pp	59.8%	80.7%
Hispanic or Latino	27,411 ±1,269	72.5% ±3.4 pp	40.2%	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: 10,652
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Married-couple family	5,117 ±430	48.0% ±3.4 pp	48.4%	46.9%
Other family: male householder, no spouse present	854 ±212	8.0% ±2.0 pp	6.3%	5.1%
Other family: female householder, no spouse present	2,556 ±428	24.0% ±3.9 pp	13.1%	12.2%
Nonfamily: householder living alone	1,684 ±334	15.8% ±3.1 pp	24.3%	28.7%
Nonfamily: householder not living alone	441 ±144	4.1% ±1.3 pp	7.9%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 10,652
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Households with people under 18	4,278 ±325	40.2% ±2.4 pp	32.4%	29.5%
Households without people under 18	6,374 ±575	59.8% ±4.7 pp	67.6%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 10,652
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
One-person nonfamily households	1,684 ±334	15.8% ±3.1 pp	24.3%	28.7%
Two-person households	2,450 ±422	23.0% ±3.8 pp	30.5%	33.8%
Three-person households	2,043 ±309	19.2% ±2.8 pp	16.7%	15.3%
Four-person households	1,630 ±307	15.3% ±2.8 pp	14.9%	12.6%
Five-person households	1,174 ±218	11.0% ±2.0 pp	7.7%	5.9%
Six-person households	1,094 ±304	10.3% ±2.8 pp	3.3%	2.2%
Seven or more people	577 ±162	5.4% ±1.5 pp	2.6%	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: 37,810
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Native	26,147 ±1,104	69.2% ±2.9 pp	73.0%	85.9%
Foreign born	11,663 ±1,105	30.8% ±2.9 pp	27.0%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 35,465
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
English only	14,926 ±1,391	42.1% ±3.9 pp	55.6%	77.7%
Spanish	16,923 ±1,341	47.7% ±3.7 pp	28.3%	13.6%
French, Haitian, or Cajun	0 ±29 · low precision	0.0% ±0.1 pp · low precision	0.4%	0.7%
German or other West Germanic	6 ±12 · low precision	0.0% ±0.0 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	94 ±110 · low precision	0.3% ±0.3 pp · low precision	0.7%	0.7%
Other Indo-European	155 ±87 · low precision	0.4% ±0.2 pp · low precision	3.5%	2.0%
Korean	80 ±64 · low precision	0.2% ±0.2 pp · low precision	1.0%	0.3%
Chinese, including Mandarin and Cantonese	1,153 ±394	3.3% ±1.1 pp	3.5%	1.1%
Vietnamese	1,055 ±439	3.0% ±1.2 pp	1.5%	0.5%
Tagalog, including Filipino	521 ±284 · low precision	1.5% ±0.8 pp · low precision	2.1%	0.6%
Other Asian and Pacific Island	293 ±157 · low precision	0.8% ±0.4 pp · low precision	2.0%	1.1%
Arabic	168 ±141 · low precision	0.5% ±0.4 pp · low precision	0.6%	0.5%
Other and unspecified	91 ±78 · low precision	0.3% ±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: 24,436
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Less than high school graduate	6,295 ±849	25.8% ±3.3 pp	15.3%	10.4%
High school graduate or equivalency	6,797 ±593	27.8% ±2.1 pp	20.5%	26.0%
Some college, no degree	4,799 ±525	19.6% ±2.0 pp	19.3%	19.1%
Associate’s degree	1,949 ±322	8.0% ±1.3 pp	7.9%	8.8%
Bachelor’s degree	2,952 ±440	12.1% ±1.7 pp	22.7%	21.6%
Graduate or professional degree	1,644 ±409	6.7% ±1.6 pp	14.4%	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: 37,288
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Same house	35,072 ±699	94.1% ±1.8 pp	89.2%	87.7%
Moved within same county	1,069 ±504	2.9% ±1.4 pp	6.4%	6.3%
Moved from a different county in the same state	683 ±296	1.8% ±0.8 pp	2.6%	3.1%
Moved from a different state	251 ±174 · low precision	0.7% ±0.5 pp · low precision	1.1%	2.3%
Moved from abroad	213 ±181 · low precision	0.6% ±0.5 pp · low precision	0.7%	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

9.5% of Montclair residents (±2.0 percentage points) had no health insurance coverage when surveyed, compared with 6.6% in California and 8.4% nationally. 92.6% 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	Montclair	California	U.S.	Compared with California
People without health insurance Civilian noninstitutionalized population	9.5% ±2.0 pp	6.6%	8.4%	Higher
Households with a broadband subscription Households	92.6% ±5.7 pp	93.5%	91.0%	Not statistically different
Veterans Civilian population age 18 and older	2.9% ±0.7 pp	4.3%	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 Montclair . 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 Montclair housing and cost context or return to the city profile.