San Mateo County Population

1860–2026

746.51K

2026 projection

2.1% since 2020 (decrease)

0200K400K600K800K186018801900192019401960198020002020

Source: U.S. Census Bureau decennial counts and annual estimates. 2026 is a projection. Values between recorded years are interpolated.

Use the left and right arrow keys to inspect population observations.

Population by year

Population estimates for San Mateo County. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
2026746,509+2,9410.40%
2025743,568+2,9410.40%
2024740,627+6,6780.91%
2023733,949+1,7040.23%
2022732,245-7,2180.98%
2021739,463-23,1763.04%
2020762,639-2,1710.28%
2019764,810-3,6000.47%
2018768,410-2480.03%
2017768,658+7300.10%

Showing 10 of 31 years.

San Mateo County Demographics

40.9median age

Median age

Female42.2 yrs
Male39.6 yrs

Adults

597,245
132,242 seniors (65+) · 22% of adults465,003 other adults

Sex

Female 50.2% · 372,465Male 49.8% · 369,875

Population by age

MaleFemale85+ years, male: 6,79985+ years, female: 11,40680–84 years, male: 7,31680–84 years, female: 8,80075–79 years, male: 9,88275–79 years, female: 13,42070–74 years, male: 14,75970–74 years, female: 18,31165–69 years, male: 20,45965–69 years, female: 21,09060–64 years, male: 22,91960–64 years, female: 23,38255–59 years, male: 24,58855–59 years, female: 25,56150–54 years, male: 25,21750–54 years, female: 25,15045–49 years, male: 24,83845–49 years, female: 24,43940–44 years, male: 26,08140–44 years, female: 26,56035–39 years, male: 29,19935–39 years, female: 26,98030–34 years, male: 29,86730–34 years, female: 27,41325–29 years, male: 25,19125–29 years, female: 23,17820–24 years, male: 20,26720–24 years, female: 19,12415–19 years, male: 21,43415–19 years, female: 19,81410–14 years, male: 21,97710–14 years, female: 20,7175–9 years, male: 19,6775–9 years, female: 18,6340–4 years, male: 19,4050–4 years, female: 18,48685+80–8475–7970–7465–6960–6455–5950–5445–4940–4435–3930–3425–2920–2415–1910–145–90–410K10K20K20K

Hover or tap an age group to see exact counts. Use the up and down arrow keys to inspect age groups.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101

Race and ethnicity

Tap a square or a group below to highlight it.

Each square is about 1% of residents (roughly 7,423 people).

Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002

San Mateo County Income

$158,855median household income

Median household income

$158,855

Half of households earn more, half earn less

Median earnings

$83,175

Typical yearly pay for a worker 25 or older.

Poverty rate

6.7%

About 1 in 15 residents

U.S. Census Bureau, 2024 ACS 5-year estimates · Tables S1901, S1501, S1701

San Mateo County Marital Status

52% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married52%53%50%
Never married34%38%31%
Divorced8%6%10%
Widowed5%2%7%
Separated2%1%2%

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201

Sources

8 sources, all from the U.S. Census Bureau

Population

American Community Survey, 2024 5-year