County profile

San Mateo County

California · ACS 2020–2024

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Latest estimates

At a glance

U.S. Census Bureau American Community Survey 5-year estimates.

Total population
742,340
Median household income
$158,855
People below poverty
6.7%
Median home value
$1,559,600

Income

The median income of households in San Mateo County, California was $158,855. An estimated 2.8% of households had income below $10,000 a year and 39.9% had income of $200,000 or more.

Household Income in San Mateo County, California in 2020-2024

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Percent
Less than $10,000 2.8
$10,000 to $14,999 1.6
$15,000 to $24,999 2.7
$25,000 to $34,999 3
$35,000 to $49,999 5.4
$50,000 to $74,999 8.7
$75,000 to $99,999 8.4
$100,000 to $149,999 15.1
$150,000 to $199,999 12.3
$200,000 or more 39.9

Median Earnings for Full-Time Year-Round Workers by Sex in San Mateo County, California in 2020-2024

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Dollars
Male 108848
Female 96317

An estimated 83.1% of households received earnings. An estimated 27.7% of households received Social Security and an estimated 23.2 % of households received retirement income other than Social Security. The average income from Social Security was $28,016. These income sources are not mutually exclusive; that is, some households received income from more than one source.

Proportion of Households with Various Income Sources in San Mateo County, California in 2020-2024

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Percent
Earnings 83.1
Social Security 27.7
Retirement income 23.2
Supplemental Security Income (SSI) 3.8
Cash public assistance income 2.7

Poverty and Participation in Government Programs

In 2020-2024, 6.7 % of people were in poverty. An estimated 6.2% of children under 18 were below the poverty level, compared with 9% of people 65 years old and over. An estimated 6.2% of people 18 to 64 years were below the poverty level.

Poverty Rates in San Mateo County, California in 2020-2024

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Percent
People in poverty 6.7
Children under 18 years below poverty 6.2
People 65 years old and over below poverty 9
People 18 to 64 years below poverty 6.2

In 2020-2024, 5.1 % of households received SNAP (the Supplemental Nutrition Assistance Program). An estimated 44% of households that received SNAP had children under 18, and 50.4% of households that received SNAP had one or more people 60 years and over. An estimated 24.5% of all households receiving SNAP were families with a female householder and no spouse present.


Among the civilian noninstitutionalized population in San Mateo County, California in 2020-2024, 96.2% had health insurance coverage and 3.8% did not have health insurance coverage. Private coverage was 78% and public coverage was 30.2%, respectively. The percentage of children under the age of 19 with no health insurance coverage was 2.2%.


In 2020-2024, San Mateo County, California had a total population of 742,340 - 372,465 (50.2%) females and 369,875 (49.8%) males. The median age was 40.9 years. An estimated 19.5% of the population was under 18 years, 34.2% was 19 to 44 years, 26.4% was 45 to 64 years, and 17.8 % was 65 years and older.

Population by Age and Sex for San Mateo County, California in 2020-2024

Male Female
Under 5 19405 18486
5 to 9 19677 18634
10 to 14 21977 20717
15 to 19 21434 19814
20 to 24 20267 19124
25 to 29 25191 23178
30 to 34 29867 27413
35 to 39 29199 26980
40 to 44 26081 26560
45 to 49 24838 24439
50 to 54 25217 25150
55 to 59 24588 25561
60 to 64 22919 23382
65 to 69 20459 21090
70 to 74 14759 18311
75 to 79 9882 13420
80 to 84 7316 8800
85 and over 6799 11406

Hispanic Origin and Race

For people reporting one race alone, 37.8% were White; 2.1% were Black or African American; 2.7% were American Indian and Alaska Native; 31.4% were Asian; 0.8% were Native Hawaiian and Other Pacific Islander, and 0% were Some Other Race. An estimated 14.4% reported Two or More Races. An estimated 24.9% of the people in San Mateo County, California were Hispanic or Latino. An estimated 34.7% of the people in San Mateo County, California were White alone, non-Hispanic. People of Hispanic origin may be of any race.


Households and Families

In 2020-2024, there were 264,419 households in San Mateo County, California. The average household size was 2.76 people.

Married-couple households made up 53.5% of the households in San Mateo County, California while cohabiting couple households made up 6.5% of households. Female householders with no spouse or partner present were 23.8% of all households, while 16.2% of households had male householders with no spouse or partner present. Some households had one person, as 10.8% of households were male householders living alone, and 13.6% were female householders living alone, for a total of 24.4% of all households.

In San Mateo County, California, 30.2% of all households had one or more people under the age of 18; 33.3% of all households had one or more people 65 years and over.

Types of Households in San Mateo County, California in 2020-2024

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Percent
Married-couple households 53.5
Cohabiting Couples 6.5
Male Householder
No spouse/partner present
16.2
Female Householder
No spouse/partner present
23.8

Marital Status

Among persons 15 and older, 52.7% of males and 50.4% of females were currently married.

Population 15 years and over Percent
Males
Percent
Females
Never married 37.5 31.1
Now married, except separated 52.7 50.4
Separated 1.3 1.7
Widowed 2.3 7.3
Divorced 6.3 9.5

Grandparents and Grandchildren

In San Mateo County, California, 16,169 grandparents lived with their grandchildren under 18 years old. Of those grandparents, 21.6% were responsible for the basic needs of their grandchildren.


Nativity and Foreign-Born

In 2020-2024, an estimated 64.3% of the people living in San Mateo County, California were U.S. natives. 48.3% of the San Mateo County, California population were living in the state where they were born.

Approximately 35.7% of San Mateo County, California residents in 2020-2024 were foreign-born. 58.3% of foreign-born were naturalized U.S. citizens and an estimated 71.9 % entered the country before the year 2010.

Foreign-born residents of San Mateo County, California come from different parts of the world. The bar graph below displays the percentage of foreign-born from each world region of birth in 2020-2024 for San Mateo County, California.

Region of Birth for the Foreign-Born Population in San Mateo County, California in 2020-2024

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Percent
Latin America 30
Asia 55.1
Europe 9.8
Africa 1.4
Northern America 1.6
Oceania 2.1

Language

Among people at least five years old living in San Mateo County, California in 2020-2024, 45.8 % spoke a language other than English at home. Spanish was spoken by 17.6% of people at least five years old; 17.1% reported that they did not speak English "very well."

Percentage of the Population 5 years and over who Speak a Language other than English in San Mateo County, California in 2020-2024

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Percent
Spanish 17.6
Other Indo-European languages 7
Asian and Pacific Islander languages 19.9
Other languages 1.2

Geographic Mobility

In 2020-2024, 88.4 % of the people at least one year old living in San Mateo County, California were living in the same house one year earlier.

Geographic Mobility of Residents of San Mateo County, California in 2020-2024

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Percent
Same house 88.4
Different house, same county 5.1
Different county, same state 3.9
Different state 1.5
Abroad 1.1

Education

In 2020-2024, 90.2 % of people 25 years and over had at least graduated from high school and 53.7% had a bachelor's degree or higher. An estimated 9.7% did not complete high school.

The total school enrollment in San Mateo County, California was 168,281 in 2020-2024. Nursery school enrollment was 11,662 and kindergarten through 12th grade enrollment was 107,226. College or graduate school enrollment was 49,393.

Educational Attainment of People in San Mateo County, California in 2020-2024

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Percent
Less than high school diploma 9.7
High school diploma or equivalency 14.7
Some college, no degree 15.1
Associate's degree 6.8
Bachelor's degree 29.6
Graduate or professional degree 24.1

Disability

In San Mateo County, California, among the civilian noninstitutionalized population in 2020-2024, 9.4 % reported a disability. The likelihood of having a disability varied by age - from 3.1% of people under 18 years old, to 6% of people 18 to 64 years old, and to 28.4% of those 65 and over.


Employment Status and Type of Employer

In San Mateo County, California, 64 % of the population 16 and over were employed; 32.7% were not currently in the labor force.

An estimated 81.3% of the people employed were private wage and salary workers; 11.6% were federal, state, or local government workers; and 6.8 % were self-employed in their own (not incorporated) business.

Class of worker Number Percent
Private wage and salary workers 319,967 81.3
Federal, state, or local government workers 45,720 11.6
Self-employed workers in own not incorporated business 26,881 6.8

Industries

In 2020-2024, the civilian employed population 16 years and older in San Mateo County, California worked in the following industries:

Percent by Industry in San Mateo County, California in 2020-2024

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Percent
Agriculture, forestry, fishing and hunting, and mining 0.6
Construction 5.4
Manufacturing 7.5
Wholesale trade 1.7
Retail trade 8.5
Transportation and warehousing, and utilities 5.8
Information 4.9
Finance and insurance, and real estate and rental and leasing 6.5
Professional, scientific, and management, and administrative and waste management services 22
Educational services, and health care and social assistance 21.4
Arts, entertainment, and recreation, and accommodation, and food services 7.8
Other Services, except public administration 4.6
Public administration 3.4

Occupations

Occupations for the Civilian Employed Population 16 Years and over in San Mateo County, California in 2020-2024

Civilian employed population 16 years and over Number Percent
Management, business, sciences, and arts occupations 217,848 55.4
Service occupations 59,656 15.2
Sales and office occupations 63,152 16.1
Natural resources, construction, and maintenance occupations 22,900 5.8
Production, transportation, and material moving occupations 29,902 7.6

Commuting to Work

An estimated 56.7% of San Mateo County, California workers drove to work alone in 2020-2024, and 8.7% carpooled. Among those who commuted to work, it took them on average 26.4 minutes to get to work.

Percent of Workers 16 and over Commuting by Mode in San Mateo County, California in 2020-2024

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Percent
Car, truck, van -- drove alone 56.7
Car, truck, van -- carpooled 8.7
Public transportation (excluding taxicab) 5.1
Walked 2.3
Other means 3
Worked from home 24.3

In 2020-2024, San Mateo County, California had a total of 287,184 housing units. Of these housing units, 64% were single-family houses either not attached to any other structure or attached to one or more structures (commonly referred to as "townhouses" or "row houses"). 34.7% of the housing units were located in multi-unit structures, or those buildings that contained two or more apartments. 1.1% were mobile homes, while any remaining housing units were classified as "other," which included boats, recreational vehicles, vans, etc.

Types of Housing Units in San Mateo County, California in 2020-2024

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Percent
Single-family houses 64
Apartments in multi-unit structures 34.7
Mobile homes 1.1
Boat, RV, van, etc 0.1

6.4% of the housing inventory was comprised of houses built since 2010, while 8.6% of the houses were first built in 1939 or earlier. The median number of rooms in all housing units in San Mateo County, California was 5 rooms, and of these housing units 53% had three or more bedrooms.


In 2020-2024, San Mateo County, California had 264,419 housing units that were occupied or had people living in them, while the remaining 22,765 were vacant. Of the occupied housing units, the percentage of these houses occupied by owners (also known as the homeownership rate) was 58.5% while renters occupied 41.5%. The average household size of owner-occupied houses was 2.89 and in renter-occupied houses it was 2.59.

4.4% of householders of these occupied houses had moved into their house since 2021, while 13.4% moved into their house in 1989 or earlier. Households without a vehicle available for personal use comprised 5.8% and another 24.8% had three or more vehicles available for use.

The following chart provides the primary fuel used to heat houses in San Mateo County, California:

House Heating Fuel Used in San Mateo County, California in 2020-2024

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Percent
Gas 64.9
Electricity 31.8
Fuel oil, kerosene, etc 0.1
All other fuels 1.2
No fuel used 2

In 2020-2024, the median property value for owner-occupied houses in San Mateo County, California was $1,559,600.

Of the owner-occupied households, 66.1 % had a mortgage. 33.9% owned their houses "free and clear," that is without a primary mortgage or loan on the house. The median monthly housing costs for owners with a mortgage was $4,000+ and for owners without a mortgage it was $1,113.

For renter-occupied houses, the median gross rent for San Mateo County, California was $2,922. Gross rent includes the monthly contract rent and any monthly payments made for electricity, gas, water and sewer, and any other fuels to heat the house.