Millbrae, California demographics

Millbrae, CA demographics: median age 43.7; 52.7% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Millbrae city, California · Incorporated city · GEOID 0647486. The survey estimates a population of 22,689 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Millbrae is 43.7 years, with a 90% margin of error of 1.8 years. There are 8,121 households (±332). 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	43.7 ±1.8	37.9 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 22,689
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Under 18	4,322 ±426	19.0% ±1.9 pp	22.0%	22.0%
18–34	4,191 ±424	18.5% ±1.9 pp	23.9%	22.8%
35–64	9,577 ±607	42.2% ±2.7 pp	38.5%	38.0%
65 and older	4,599 ±434	20.3% ±1.9 pp	15.7%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 22,689
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Male	10,989 ±409	48.4% ±1.8 pp	49.9%	49.5%
Female	11,700 ±407	51.6% ±1.8 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: 22,689
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
White alone	6,963 ±696	30.7% ±3.1 pp	39.7%	61.0%
Black or African American alone	201 ±132 · low precision	0.9% ±0.6 pp · low precision	5.4%	12.2%
American Indian and Alaska Native alone	72 ±59 · low precision	0.3% ±0.3 pp · low precision	1.3%	0.9%
Asian alone	10,926 ±844	48.2% ±3.7 pp	15.5%	6.0%
Native Hawaiian and Other Pacific Islander alone	428 ±276 · low precision	1.9% ±1.2 pp · low precision	0.4%	0.2%
Some other race alone	1,547 ±575	6.8% ±2.5 pp	18.5%	7.1%
Two or more races	2,552 ±448	11.2% ±2.0 pp	19.2%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 22,689
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Not Hispanic or Latino	19,531 ±579	86.1% ±2.5 pp	59.8%	80.7%
Hispanic or Latino	3,158 ±577	13.9% ±2.5 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: 8,121
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Married-couple family	4,419 ±281	54.4% ±2.7 pp	48.4%	46.9%
Other family: male householder, no spouse present	305 ±104	3.8% ±1.3 pp	6.3%	5.1%
Other family: female householder, no spouse present	820 ±199	10.1% ±2.4 pp	13.1%	12.2%
Nonfamily: householder living alone	2,026 ±344	24.9% ±4.1 pp	24.3%	28.7%
Nonfamily: householder not living alone	551 ±170	6.8% ±2.1 pp	7.9%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 8,121
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Households with people under 18	2,368 ±215	29.2% ±2.4 pp	32.4%	29.5%
Households without people under 18	5,753 ±413	70.8% ±4.2 pp	67.6%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 8,121
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
One-person nonfamily households	2,026 ±344	24.9% ±4.1 pp	24.3%	28.7%
Two-person households	2,291 ±308	28.2% ±3.6 pp	30.5%	33.8%
Three-person households	1,445 ±215	17.8% ±2.5 pp	16.7%	15.3%
Four-person households	1,580 ±229	19.5% ±2.7 pp	14.9%	12.6%
Five-person households	613 ±140	7.5% ±1.7 pp	7.7%	5.9%
Six-person households	95 ±51 · low precision	1.2% ±0.6 pp · low precision	3.3%	2.2%
Seven or more people	71 ±39 · low precision	0.9% ±0.5 pp · low precision	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: 22,689
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Native	13,431 ±641	59.2% ±2.8 pp	73.0%	85.9%
Foreign born	9,258 ±642	40.8% ±2.8 pp	27.0%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 21,377
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
English only	10,975 ±700	51.3% ±3.2 pp	55.6%	77.7%
Spanish	1,864 ±493	8.7% ±2.3 pp	28.3%	13.6%
French, Haitian, or Cajun	39 ±36 · low precision	0.2% ±0.2 pp · low precision	0.4%	0.7%
German or other West Germanic	38 ±34 · low precision	0.2% ±0.2 pp · low precision	0.3%	0.5%
Russian, Polish, or other Slavic	201 ±179 · low precision	0.9% ±0.8 pp · low precision	0.7%	0.7%
Other Indo-European	983 ±380	4.6% ±1.8 pp	3.5%	2.0%
Korean	295 ±158 · low precision	1.4% ±0.7 pp · low precision	1.0%	0.3%
Chinese, including Mandarin and Cantonese	5,142 ±622	24.1% ±2.9 pp	3.5%	1.1%
Vietnamese	122 ±81 · low precision	0.6% ±0.4 pp · low precision	1.5%	0.5%
Tagalog, including Filipino	868 ±355	4.1% ±1.7 pp	2.1%	0.6%
Other Asian and Pacific Island	494 ±185	2.3% ±0.9 pp	2.0%	1.1%
Arabic	333 ±155	1.6% ±0.7 pp	0.6%	0.5%
Other and unspecified	23 ±27 · 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: 16,852
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Less than high school graduate	1,077 ±276	6.4% ±1.6 pp	15.3%	10.4%
High school graduate or equivalency	2,739 ±416	16.3% ±2.4 pp	20.5%	26.0%
Some college, no degree	2,792 ±424	16.6% ±2.5 pp	19.3%	19.1%
Associate’s degree	1,366 ±208	8.1% ±1.2 pp	7.9%	8.8%
Bachelor’s degree	5,233 ±443	31.1% ±2.5 pp	22.7%	21.6%
Graduate or professional degree	3,645 ±381	21.6% ±2.2 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: 22,435
Category	Count ± MOE	Share ± MOE (pp)	California	U.S.
Same house	19,806 ±632	88.3% ±2.8 pp	89.2%	87.7%
Moved within same county	1,345 ±390	6.0% ±1.7 pp	6.4%	6.3%
Moved from a different county in the same state	791 ±255	3.5% ±1.1 pp	2.6%	3.1%
Moved from a different state	156 ±111 · low precision	0.7% ±0.5 pp · low precision	1.1%	2.3%
Moved from abroad	337 ±192 · low precision	1.5% ±0.9 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

3.6% of Millbrae residents (±0.9 percentage points) had no health insurance coverage when surveyed, compared with 6.6% in California and 8.4% nationally. 93.6% 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	Millbrae	California	U.S.	Compared with California
People without health insurance Civilian noninstitutionalized population	3.6% ±0.9 pp	6.6%	8.4%	Lower
Households with a broadband subscription Households	93.6% ±5.3 pp	93.5%	91.0%	Not statistically different
Veterans Civilian population age 18 and older	2.6% ±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 Millbrae . 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 Millbrae housing and cost context or return to the city profile.