City · California
Foster City, California
Foster City, city, in San Mateo County, California. Foster City had 32,411 residents on July 1, 2025 by the Census Bureau's estimate, down 4.1% since 2020; the 2020 Census counted 33,805 and the ACS 2020-2024 5-year estimates put it at 32,792 (±53). GEOID 0625338.
Residents, July 2025 estimate
32,411
Census Bureau estimate (no margin published)
2020 Census count: 33,805 · ACS 2020-2024: 32,792 ±53
Median household income
$199,143
±$11,786 (90% margin)
California: $99,122
Median home value
$1,838,200
±$78,375 (90% margin)
California: $734,700
Median gross rent
$3,500 or more
The survey's top or bottom value; no margin is published
California: $2,036
Where is Foster City and what county is it in?
Foster City is a city in San Mateo County, California. It covers 3.8 square miles of land, 8,927 residents per square mile in 2020.
Foster City is in the San Francisco-Oakland-Fremont, CA metropolitan statistical area, which takes in 5 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 Foster City, and is it growing?
The Census Bureau estimates that 32,411 people lived in Foster City on July 1, 2025, down 4.1% since 2020, a steeper fall than California's (−0.5%). The 2020 Census counted 33,805 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 32,792 (±53).
| Measure | Foster City | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 32,792 ±53 | 742,340 | −1,205 |
| Households | 12,998 ±333 | 264,419 | no clear change |
| Average household size | 2.51 ±0.07 | 2.76 | −0.15 |
| Housing units | 13,617 ±370 | 287,184 | no clear change |
Foster City's population since 2000
From 28,803 in 2000 to 32,411 in 2025: up 12.5%. The 2000, 2010 and 2020 figures are census counts, each for Foster City as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
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 Foster City?
The median resident of Foster City is 39.5 years old; 22.2% are under 18 and 17.6% are 65 or older. The largest group is non-Hispanic Asian residents at 54.3%, then non-Hispanic white residents at 28.9%. 49.5% of residents were born outside the United States.
| Measure | Foster City | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 39.5 ±1.5 | 40.9 | no clear change |
| Under 18 years | 22.2% ±1.9 pts | 19.5% | – |
| 65 years and over | 17.6% ±1.3 pts | 17.8% | – |
| Male | 47.8% ±1.6 pts | 49.8% | – |
| Hispanic or Latino (any race) | 7.1% ±1.4 pts | 24.9% | no clear change |
| White alone, not Hispanic | 28.9% ±2.3 pts | 34.7% | −8.0 pts |
| Black or African American alone, not Hispanic | 1.6% ±0.7 pts | 2.0% | no clear change |
| Asian alone, not Hispanic | 54.3% ±2.6 pts | 31.0% | +6.8 pts |
| American Indian and Alaska Native alone, not Hispanic | 0.2% ±0.2 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.1% ±0.2 pts | 1.1% | – |
| Two or more races, not Hispanic | 6.3% ±1.3 pts | 5.2% | – |
| Some other race alone, not Hispanic | 1.4% ±0.8 pts | 0.9% | – |
| Born outside the United States | 49.5% ±2.4 pts | 35.7% | +4.4 pts |
| Speak a language other than English at home (age 5+) | 55.0% ±2.3 pts | 45.8% | – |
| Civilian veterans (age 18+) | 2.4% ±0.6 pts | 2.9% | – |
| With a disability | 8.7% ±0.9 pts | 9.4% | – |
| No health insurance coverage | 2.2% ±0.7 pts | 3.8% | no clear change |
| High school graduate or higher (age 25+) | 96.2% ±1.2 pts | 90.2% | – |
| Bachelor's degree or higher (age 25+) | 73.8% ±2.1 pts | 53.7% | +3.5 pts |
| Graduate or professional degree (age 25+) | 40.6% ±2.4 pts | 24.1% | – |
| Lived in the same house a year earlier | 81.5% ±2.4 pts | 88.4% | – |
| Moved from another state in the past year | 2.4% ±0.7 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 Foster City earn?
Half of Foster City's 12,998 households earn less than $199,143 a year (±$11,786), against $158,855 in San Mateo County and $99,122 in California. In 2015-2019 it was $195,101 in 2024 dollars; the margins of error cannot tell the two periods apart. 4.1% of residents live below the poverty line.
| Measure | Foster City | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $199,143 ±$11,786 | $158,855 | no clear change |
| Mean household income | $246,457 ±$11,514 | $231,822 | – |
| Per capita income | $98,585 ±$4,705 | $84,288 | +$11,569 |
| People below the poverty line | 4.1% ±1.1 pts | 6.7% | no clear change |
| Children under 18 below the poverty line | 1.9% ±1.6 pts | 6.2% | – |
| Households receiving SNAP | 1.0% ±0.5 pts | 5.1% | – |
| Households with a computer | 99.0% ±0.6 pts | 97.7% | – |
| Households with a broadband subscription | 98.1% ±0.9 pts | 95.7% | – |
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 Foster City?
Owners occupy 50.8% of Foster City's occupied homes and renters 49.2%. The median owner-occupied home is valued at $1,838,200 by its owner (±$78,375). The median renter pays $3,500 or more a month including utilities, and 33.9% of renters pay 35% or more of their income on rent.
| Measure | Foster City | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $1,838,200 ±$78,375 | $1,559,600 | +$305,002 |
| Median gross rent | $3,500 or more | $2,922 | −$448 |
| Renters paying 35% or more of income on rent | 33.9% ±5.0 pts | 40.3% | +8.7 pts |
| Median monthly owner costs, with a mortgage | $4,000 or more | $4,000 or more | – |
| Owner-occupied homes | 50.8% ±2.7 pts | 58.5% | −6.3 pts |
| Renter-occupied homes | 49.2% ±2.7 pts | 41.5% | – |
| Housing units | 13,617 ±370 | 287,184 | no clear change |
| Homeowner vacancy rate | 0.1% ±0.1 pts | 0.7% | – |
| Rental vacancy rate | 6.4% ±2.6 pts | 8.5% | – |
| Single-family detached homes | 35.0% ±2.1 pts | 55.3% | – |
| Mobile homes | 0.0% ±0.3 pts | 1.1% | – |
| Built 2020 or later | 1.2% ±0.8 pts | 1.0% | – |
| Built 2010 to 2019 | 7.7% ±1.5 pts | 5.4% | – |
| Built 1939 or earlier | 0.8% ±0.5 pts | 8.6% | – |
| Households with no vehicle | 5.7% ±1.6 pts | 5.8% | – |
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 many new homes is Foster City building?
Builders took permits for 7 new housing units in Foster City in 2025 (7 in single-family houses), 0.2 per 1,000 residents against 2.6 across California.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Foster City work and get to work?
51.8% of Foster City's workers drive alone and 34.2% work from home. The average trip to work takes 29.4 minutes. The unemployment rate in 2020-2024 averaged 4.9%.
| Measure | Foster City | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 67.4% ±1.9 pts | 67.3% | – |
| Unemployment rate | 4.9% ±1.2 pts | 4.8% | +1.8 pts |
| Drove alone to work | 51.8% ±3.3 pts | 56.7% | – |
| Carpooled | 7.5% ±1.7 pts | 8.7% | – |
| Public transportation | 2.9% ±0.8 pts | 5.1% | – |
| Walked | 1.7% ±0.8 pts | 2.3% | – |
| Worked from home | 34.2% ±2.9 pts | 24.3% | +28.4 pts |
| Mean travel time to work | 29.4 min ±1.4 | 26.4 min | −3.9 min |
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 Foster City?
9 census tracts lie mostly in Foster City, and 2 more reach into it (2020 census blocks). Their median household incomes run from $149,896 (Tract 6080.25) to $250,000 or more (Tract 6080.23).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 6080.25San Mateo County | 6,212 | $149,896 |
| Tract 6080.13San Mateo County | 3,744 | $180,156 |
| Tract 6080.02San Mateo County | 3,665 | $242,826 |
| Tract 6082San Mateo County | 3,606 | $233,094 |
| Tract 6080.01San Mateo County | 3,387 | $192,981 |
| Tract 6081San Mateo County | 3,325 | $209,074 |
| Tract 6083San Mateo County | 3,305 | $196,101 |
| Tract 6080.24San Mateo County | 3,200 | $204,659 |
| Tract 6080.23San Mateo County | 2,348 | $250,000 or more |
| Tract 6079San Mateo County | 3,089 | $152,610 |
| Tract 9901San Mateo County | 0 | not published |
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 Foster City) · Census block assignment files
How does Foster City compare with other places in California?
By the Census Bureau's July 2025 estimates, Foster City is the 1,274th-most populous of the 19,476 U.S. incorporated places that have one and the 229th-most populous of 483 in California.
Foster City ranks 74th of 1,037 places in California with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 229th | 483 |
| Growth 2020-2025 (PEP) | 369th | 469 |
| Residents per square mile | 86th | 1,077 |
| Median household income | 74th | 1,037 |
| Per capita income | 85th | 1,073 |
| Median home value | 74th | 1,054 |
| Median gross rent | 1st | 987 |
| Poverty rate | 805th | 836 |
| Bachelor's degree or higher | 62nd | 988 |
| Median age | 547th | 1,075 |
| Owner-occupied share | 888th | 1,064 |
| Work from home | 74th | 822 |
| Travel time to work | 419th | 1,069 |
Foster City's figures with every place in California (CSV)
Every place in California, sortable · Compare Foster City 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 Foster City?
6 of the 57 figures for Foster City 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 Foster City 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' public schools in Foster City.