City · California
South San Francisco, California
South San Francisco, city, in San Mateo County, California. South San Francisco had 64,941 residents on July 1, 2025 by the Census Bureau's estimate, down 1.8% since 2020; the 2020 Census counted 66,105 and the ACS 2020-2024 5-year estimates put it at 64,305 (±49). GEOID 0673262.
Residents, July 2025 estimate
64,941
Census Bureau estimate (no margin published)
2020 Census count: 66,105 · ACS 2020-2024: 64,305 ±49
Median household income
$136,578
±$7,930 (90% margin)
California: $99,122
Median home value
$1,188,800
±$21,662 (90% margin)
California: $734,700
Median gross rent
$2,802
±$140 (90% margin)
California: $2,036
Where is South San Francisco and what county is it in?
South San Francisco is a city in San Mateo County, California. It covers 9.2 square miles of land, 7,182 residents per square mile in 2020.
South San Francisco 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 South San Francisco, and is it growing?
The Census Bureau estimates that 64,941 people lived in South San Francisco on July 1, 2025, down 1.8% since 2020, a steeper fall than California's (−0.5%). The 2020 Census counted 66,105 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 64,305 (±49).
| Measure | South San Francisco | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 64,305 ±49 | 742,340 | −3,103 |
| Households | 21,838 ±653 | 264,419 | no clear change |
| Average household size | 2.90 ±0.09 | 2.76 | −0.22 |
| Housing units | 23,515 ±660 | 287,184 | +1,345 |
South San Francisco's population since 2000
From 60,552 in 2000 to 64,941 in 2025: up 7.2%. The 2000, 2010 and 2020 figures are census counts, each for South San Francisco 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 South San Francisco?
The median resident of South San Francisco is 43.2 years old; 17.2% are under 18 and 19.2% are 65 or older. The largest group is non-Hispanic Asian residents at 41.8%, then Hispanic or Latino residents (of any race) at 32.1%. 40.2% of residents were born outside the United States.
| Measure | South San Francisco | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 43.2 ±1.4 | 40.9 | +2.8 |
| Under 18 years | 17.2% ±1.0 pts | 19.5% | – |
| 65 years and over | 19.2% ±1.1 pts | 17.8% | – |
| Male | 50.1% ±1.2 pts | 49.8% | – |
| Hispanic or Latino (any race) | 32.1% ±2.3 pts | 24.9% | no clear change |
| White alone, not Hispanic | 20.0% ±1.7 pts | 34.7% | no clear change |
| Black or African American alone, not Hispanic | 1.5% ±0.6 pts | 2.0% | no clear change |
| Asian alone, not Hispanic | 41.8% ±2.1 pts | 31.0% | no clear change |
| American Indian and Alaska Native alone, not Hispanic | 0.1% ±0.1 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.6% ±0.5 pts | 1.1% | – |
| Two or more races, not Hispanic | 3.5% ±1.0 pts | 5.2% | – |
| Some other race alone, not Hispanic | 0.3% ±0.2 pts | 0.9% | – |
| Born outside the United States | 40.2% ±2.2 pts | 35.7% | no clear change |
| Speak a language other than English at home (age 5+) | 53.8% ±2.3 pts | 45.8% | – |
| Civilian veterans (age 18+) | 2.5% ±0.6 pts | 2.9% | – |
| With a disability | 10.8% ±1.0 pts | 9.4% | – |
| No health insurance coverage | 3.1% ±0.9 pts | 3.8% | −1.5 pts |
| High school graduate or higher (age 25+) | 86.0% ±1.8 pts | 90.2% | – |
| Bachelor's degree or higher (age 25+) | 40.8% ±2.1 pts | 53.7% | +5.2 pts |
| Graduate or professional degree (age 25+) | 12.6% ±1.4 pts | 24.1% | – |
| Lived in the same house a year earlier | 92.1% ±1.2 pts | 88.4% | – |
| Moved from another state in the past year | 0.9% ±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 South San Francisco earn?
Half of South San Francisco's 21,838 households earn less than $136,578 a year (±$7,930), against $158,855 in San Mateo County and $99,122 in California. In 2015-2019 it was $129,788 in 2024 dollars; the margins of error cannot tell the two periods apart. 6.7% of residents live below the poverty line.
| Measure | South San Francisco | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $136,578 ±$7,930 | $158,855 | no clear change |
| Mean household income | $177,602 ±$14,402 | $231,822 | – |
| Per capita income | $62,611 ±$5,656 | $84,288 | +$9,738 |
| People below the poverty line | 6.7% ±1.2 pts | 6.7% | no clear change |
| Children under 18 below the poverty line | 7.5% ±2.7 pts | 6.2% | no clear change |
| Households receiving SNAP | 6.4% ±1.0 pts | 5.1% | – |
| Households with a computer | 97.0% ±0.9 pts | 97.7% | – |
| Households with a broadband subscription | 95.6% ±1.1 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 South San Francisco?
Owners occupy 59.0% of South San Francisco's occupied homes and renters 41.0%. The median owner-occupied home is valued at $1,188,800 by its owner (±$21,662). The median renter pays $2,802 a month including utilities, and 42.6% of renters pay 35% or more of their income on rent.
| Measure | South San Francisco | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $1,188,800 ±$21,662 | $1,559,600 | +$150,094 |
| Median gross rent | $2,802 ±$140 | $2,922 | +$211 |
| Renters paying 35% or more of income on rent | 42.6% ±4.4 pts | 40.3% | no clear change |
| Median monthly owner costs, with a mortgage | $3,731 ±$157 | $4,000 or more | – |
| Owner-occupied homes | 59.0% ±2.2 pts | 58.5% | no clear change |
| Renter-occupied homes | 41.0% ±2.2 pts | 41.5% | – |
| Housing units | 23,515 ±660 | 287,184 | +1,345 |
| Homeowner vacancy rate | 0.0% ±0.3 pts | 0.7% | – |
| Rental vacancy rate | 7.3% ±1.9 pts | 8.5% | – |
| Single-family detached homes | 58.5% ±2.3 pts | 55.3% | – |
| Mobile homes | 1.2% ±0.7 pts | 1.1% | – |
| Built 2020 or later | 2.1% ±0.7 pts | 1.0% | – |
| Built 2010 to 2019 | 5.0% ±1.1 pts | 5.4% | – |
| Built 1939 or earlier | 6.9% ±1.2 pts | 8.6% | – |
| Households with no vehicle | 7.5% ±1.4 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 South San Francisco building?
Builders took permits for 585 new housing units in South San Francisco in 2025 (42 in single-family houses), 9.0 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 South San Francisco work and get to work?
61.4% of South San Francisco's workers drive alone and 17.4% work from home. The average trip to work takes 25.6 minutes. The unemployment rate in 2020-2024 averaged 2.8%.
| Measure | South San Francisco | San Mateo County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 67.0% ±1.3 pts | 67.3% | – |
| Unemployment rate | 2.8% ±0.6 pts | 4.8% | no clear change |
| Drove alone to work | 61.4% ±2.1 pts | 56.7% | – |
| Carpooled | 11.4% ±1.6 pts | 8.7% | – |
| Public transportation | 5.5% ±1.3 pts | 5.1% | – |
| Walked | 1.9% ±0.6 pts | 2.3% | – |
| Worked from home | 17.4% ±2.1 pts | 24.3% | +14.1 pts |
| Mean travel time to work | 25.6 min ±0.9 | 26.4 min | −3.4 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 South San Francisco?
14 census tracts lie mostly in South San Francisco, and 2 more reach into it (2020 census blocks). Their median household incomes run from $82,679 (Tract 6021) to $186,974 (Tract 6017).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 6024San Mateo County | 7,339 | $120,699 |
| Tract 6018San Mateo County | 6,025 | $143,138 |
| Tract 6025San Mateo County | 5,331 | $161,279 |
| Tract 6022.01San Mateo County | 5,250 | $92,617 |
| Tract 6019.02San Mateo County | 4,960 | $125,096 |
| Tract 6017San Mateo County | 4,461 | $186,974 |
| Tract 6026.02San Mateo County | 4,289 | $170,274 |
| Tract 6023San Mateo County | 4,245 | $146,750 |
| Tract 6020.01San Mateo County | 4,147 | $176,389 |
| Tract 6019.01San Mateo County | 3,951 | $103,472 |
| Tract 6026.01San Mateo County | 3,932 | $149,044 |
| Tract 6021San Mateo County | 3,262 | $82,679 |
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 South San Francisco) · Census block assignment files
How does South San Francisco compare with other places in California?
By the Census Bureau's July 2025 estimates, South San Francisco is the 614th-most populous of the 19,476 U.S. incorporated places that have one and the 138th-most populous of 483 in California.
South San Francisco ranks 195th 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 | 138th | 483 |
| Growth 2020-2025 (PEP) | 243rd | 469 |
| Residents per square mile | 132nd | 1,077 |
| Median household income | 195th | 1,037 |
| Per capita income | 250th | 1,073 |
| Median home value | 160th | 1,054 |
| Median gross rent | 133rd | 987 |
| Poverty rate | 665th | 836 |
| Bachelor's degree or higher | 339th | 988 |
| Median age | 375th | 1,075 |
| Owner-occupied share | 698th | 1,064 |
| Work from home | 368th | 822 |
| Travel time to work | 684th | 1,069 |
South San Francisco's figures with every place in California (CSV)
Every place in California, sortable · Compare South San Francisco 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 South San Francisco?
5 of the 57 figures for South San Francisco 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 South San Francisco 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 South San Francisco.