Census-designated place · California
Alum Rock, California
Alum Rock, census-designated place, in Santa Clara County, California. Alum Rock had 10,440 people in the ACS 2020-2024 5-year estimates (±1,158). GEOID 0601458.
Residents, 2020-2024
10,440
±1,158 (90% margin)
2020 Census count: 12,042
Median household income
$126,705
±$23,062 (90% margin)
California: $99,122
Median home value
$909,500
±$39,854 (90% margin)
California: $734,700
Median gross rent
$2,389
±$170 (90% margin)
California: $2,036
Where is Alum Rock and what county is it in?
Alum Rock is a census-designated place: an unincorporated community the Census Bureau draws for counting, with no city government of its own, in Santa Clara County, California. It covers 0.9 square miles of land, 13,857 residents per square mile in 2020.
Alum Rock is in the San Jose-Sunnyvale-Santa Clara, CA metropolitan statistical area, which takes in 2 counties (Census Bureau delineation, July 2023).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Alum Rock, and is it growing?
The 2020-2024 American Community Survey puts Alum Rock's population at 10,440 (±1,158). The 2020 Census counted 12,042 residents.
The Census Bureau publishes yearly population estimates for incorporated places only; Alum Rock is a census-designated place, so its figures come from the ACS and the 2020 Census.
| Measure | Alum Rock | Santa Clara County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 10,440 ±1,158 | 1,902,047 | no clear change |
| Households | 2,648 ±277 | 659,353 | no clear change |
| Average household size | 3.84 ±0.33 | 2.82 | no clear change |
| Housing units | 2,896 ±267 | 698,837 | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Alum Rock?
The median resident of Alum Rock is 41.0 years old; 18.3% are under 18 and 18.5% are 65 or older. The largest group is Hispanic or Latino residents (of any race) at 63.6%, then non-Hispanic Asian residents at 21.1%. 41.9% of residents were born outside the United States.
| Measure | Alum Rock | Santa Clara County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 41.0 ±3.1 | 38.1 | +8.1 |
| Under 18 years | 18.3% ±3.0 pts | 20.5% | – |
| 65 years and over | 18.5% ±3.4 pts | 14.8% | – |
| Male | 51.7% ±2.7 pts | 51.0% | – |
| Hispanic or Latino (any race) | 63.6% ±5.9 pts | 25.0% | −8.1 pts |
| White alone, not Hispanic | 12.0% ±2.9 pts | 27.2% | no clear change |
| Black or African American alone, not Hispanic | 0.3% ±0.4 pts | 2.2% | – |
| Asian alone, not Hispanic | 21.1% ±5.8 pts | 40.3% | no clear change |
| American Indian and Alaska Native alone, not Hispanic | 0.1% ±0.1 pts | 0.2% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.2% ±0.3 pts | 0.4% | – |
| Two or more races, not Hispanic | 0.7% ±0.6 pts | 4.2% | – |
| Some other race alone, not Hispanic | 2.1% ±2.0 pts | 0.6% | – |
| Born outside the United States | 41.9% ±4.7 pts | 41.5% | no clear change |
| Speak a language other than English at home (age 5+) | 65.8% ±5.9 pts | 55.2% | – |
| Civilian veterans (age 18+) | 2.9% ±1.3 pts | 2.6% | – |
| With a disability | 9.6% ±1.9 pts | 9.0% | – |
| No health insurance coverage | 6.1% ±2.2 pts | 3.9% | no clear change |
| High school graduate or higher (age 25+) | 68.8% ±5.2 pts | 89.3% | – |
| Bachelor's degree or higher (age 25+) | 24.7% ±4.5 pts | 56.5% | +8.5 pts |
| Graduate or professional degree (age 25+) | 8.2% ±2.7 pts | 28.3% | – |
| Lived in the same house a year earlier | 92.6% ±2.8 pts | 86.0% | – |
| Moved from another state in the past year | 0.6% ±0.6 pts | 1.5% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Alum Rock earn?
Half of Alum Rock's 2,648 households earn less than $126,705 a year (±$23,062), against $164,281 in Santa Clara County and $99,122 in California. In 2015-2019 it was $111,261 in 2024 dollars; the margins of error cannot tell the two periods apart. 6.2% of residents live below the poverty line.
| Measure | Alum Rock | Santa Clara County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $126,705 ±$23,062 | $164,281 | no clear change |
| Mean household income | $145,202 ±$16,390 | $227,007 | – |
| Per capita income | $39,114 ±$4,142 | $80,312 | +$6,781 |
| People below the poverty line | 6.2% ±2.4 pts | 7.1% | −5.3 pts |
| Children under 18 below the poverty line | 3.4% ±3.5 pts | 7.0% | – |
| Households receiving SNAP | 17.1% ±7.8 pts | 6.6% | – |
| Households with a computer | 97.1% ±2.7 pts | 98.0% | – |
| Households with a broadband subscription | 88.8% ±4.6 pts | 95.6% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Alum Rock?
Owners occupy 70.2% of Alum Rock's occupied homes and renters 29.8%. The median owner-occupied home is valued at $909,500 by its owner (±$39,854). The median renter pays $2,389 a month including utilities, and 45.2% of renters pay 35% or more of their income on rent.
| Measure | Alum Rock | Santa Clara County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $909,500 ±$39,854 | $1,490,600 | +$129,486 |
| Median gross rent | $2,389 ±$170 | $2,857 | no clear change |
| Renters paying 35% or more of income on rent | 45.2% ±13.5 pts | 36.4% | no clear change |
| Median monthly owner costs, with a mortgage | $3,005 ±$365 | $4,000 or more | – |
| Owner-occupied homes | 70.2% ±6.4 pts | 55.1% | no clear change |
| Renter-occupied homes | 29.8% ±6.4 pts | 44.9% | – |
| Housing units | 2,896 ±267 | 698,837 | no clear change |
| Homeowner vacancy rate | 0.0% ±2.2 pts | 0.7% | – |
| Rental vacancy rate | 3.5% ±3.4 pts | 5.1% | – |
| Single-family detached homes | 87.8% ±4.4 pts | 50.7% | – |
| Mobile homes | 0.4% ±0.7 pts | 2.8% | – |
| Built 2020 or later | 0.0% ±1.5 pts | 1.5% | – |
| Built 2010 to 2019 | 2.3% ±2.6 pts | 9.1% | – |
| Built 1939 or earlier | 9.9% ±3.9 pts | 4.7% | – |
| Households with no vehicle | 2.3% ±1.9 pts | 6.0% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How do people in Alum Rock work and get to work?
75.9% of Alum Rock's workers drive alone and 7.7% work from home. The average trip to work takes 27.9 minutes. The unemployment rate in 2020-2024 averaged 4.5%.
| Measure | Alum Rock | Santa Clara County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 64.3% ±3.9 pts | 67.4% | – |
| Unemployment rate | 4.5% ±1.7 pts | 4.9% | no clear change |
| Drove alone to work | 75.9% ±4.5 pts | 59.9% | – |
| Carpooled | 11.3% ±3.4 pts | 9.0% | – |
| Public transportation | 0.5% ±0.5 pts | 2.3% | – |
| Walked | 2.0% ±1.7 pts | 2.1% | – |
| Worked from home | 7.7% ±2.7 pts | 23.9% | – |
| Mean travel time to work | 27.9 min ±2.2 | 26.2 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Alum Rock?
3 census tracts lie mostly in Alum Rock, and 1 more reaches into it (2020 census blocks). Their median household incomes run from $121,083 (Tract 5039.02) to $156,450 (Tract 5041.02).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 5039.02Santa Clara County | 6,187 | $121,083 |
| Tract 5041.02Santa Clara County | 5,273 | $156,450 |
| Tract 5041.01Santa Clara County | 3,628 | $144,167 |
| Tract 5038.02Santa Clara County | 7,647 | $114,023 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Alum Rock) · Census block assignment files
How does Alum Rock compare with other places in California?
Alum Rock ranks 250th of 1,037 places in California with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population (ACS 2020-2024) | 488th | 1,076 |
| Residents per square mile | 21st | 1,077 |
| Median household income | 250th | 1,037 |
| Per capita income | 607th | 1,073 |
| Median home value | 273rd | 1,054 |
| Median gross rent | 239th | 987 |
| Poverty rate | 690th | 836 |
| Bachelor's degree or higher | 609th | 988 |
| Median age | 475th | 1,075 |
| Owner-occupied share | 444th | 1,064 |
| Work from home | 701st | 822 |
| Travel time to work | 528th | 1,069 |
Alum Rock's figures with every place in California (CSV)
Every place in California, sortable · Compare Alum Rock with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Alum Rock?
15 of the 57 figures for Alum Rock on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Alum Rock are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.