San Mateo County's 2026 population is estimated at 760,145, reflecting a 1.15% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). San Mateo County is the 15th largest county in California. The 2010 population was 719,948 and has grown 5.58% since 2010.
Data after 2023 is projected based on recent change
Overall: 40.9 years
Female: 42.2 years
Male: 39.6 years
There are 597,245 adults, (132,242 of whom are seniors) in San Mateo County.
Female: 372,465 (50.2%)
Male: 369,875 (49.8%)
The racial composition of San Mateo County includes 37.84% White, 31.38% Asian, 11.94% other race, and smaller percentages for Black or African American, Native Hawaiian or Pacific Islander, Native American and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 280,904 | 37.84% |
| Asian | 232,971 | 31.38% |
| Two or more races | 107,200 | 14.44% |
| Other race | 88,602 | 11.94% |
| Black or African American | 15,785 | 2.13% |
| Native Hawaiian or Pacific Islander | 8,444 | 1.14% |
| Native American | 8,434 | 1.14% |
San Mateo County 's average per capita income is $83,175. Household income levels show a median of $158,855. The poverty rate stands at 6.71%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $218,404 | $301,038 |
| Families | $189,508 | $267,578 |
| Households | $158,855 | $231,822 |
| Non Families | $98,495 | $144,014 |
Average Income
Median Household Income
Poverty Rate