County hub suburban California

San Mateo County, CA

Aggregated demographic, housing, and geographic context for the 30 ZIP codes inside San Mateo County, drawn from public Census ACS and SimpleMaps data.

ZIP codes
30
in this county
Total population
732,609
across all listed ZIPs
Cities
23
distinct city/town names
Avg density
1,658
people / sq mi
Avg median income
$122,103
household, ACS
Avg home value
$1,114,400
owner-occupied

ZIP codes in San Mateo County

ZIPCityPopulationDensityMedian income
94080 South San Francisco 66,652 2,529 $126,916
94015 Daly City 64,754 4,421 $117,289
94014 Daly City 47,708 2,882
94403 San Mateo 44,244 3,033
94066 San Bruno 43,846 2,793
94010 Burlingame 43,644 1,115
94025 Menlo Park 41,826 1,931
94044 Pacifica 38,609 988
94061 Redwood City 38,255 3,826
94404 San Mateo 36,571 3,246
94063 Redwood City 35,163 2,088
94401 San Mateo 35,095 4,356
94070 San Carlos 31,477 1,986
94002 Belmont 28,201 1,936
94402 San Mateo 27,188 2,077
94062 Redwood City 26,847 160
94030 Millbrae 23,083 2,641
94019 Half Moon Bay 15,452 100
94065 Redwood City 11,772 1,982
94027 Atherton 7,213 554
94028 Portola Valley 6,582 147
94005 Brisbane 4,803 405
94018 El Granada 3,636 2,425
94038 Moss Beach 3,227 210
94037 Montara 2,879 202
94020 La Honda 2,186 20
94060 Pescadero 1,293 7
94021 Loma Mar 263 9
94074 San Gregorio 140 2
94128 San Francisco

About San Mateo County

Counties are the workhorse unit of American local government — they administer property taxes, run the courts and sheriff’s office, manage many road and library systems, and in much of the country they collect public health and zoning data that ZIP codes don’t. San Mateo County in California contains roughly 30 ZIP codes spread across 23 distinct cities and unincorporated communities, with an aggregate population of about 732,609. Reading those ZIPs together at the county level smooths over neighborhood-by-neighborhood noise and surfaces the broader economic and demographic shape of the area. For block-level detail, drill into any individual ZIP profile or compare against the wider California index.

The average density across listed ZIPs sits at roughly 1,658, which classifies the county overall as a suburban environment. That label is a generalization — nearly every county contains both a relatively dense core and quieter outlying ZIPs, and the gap between them is often what determines where you actually want to live or open a business. Average median household income in our enriched ZIPs lands near $122,103, with average owner-occupied home values around $1,114,400; both numbers move dramatically as you cross from one ZIP to the next, so use the table above as a sorting tool, not a verdict.

If you’re moving into San Mateo County, the county itself is also where most of your real-life paperwork will land — vehicle registration, voter registration, property recording, and school district enrollment in many states. Knowing the county that contains your prospective ZIP makes it much easier to look up the right tax assessor, election office, or school district website. Our relocation guide walks through the order in which to tackle these handoffs after a move.

For service-area planning, the county is also where most US business licensing and many sales-tax rules are administered. Service businesses scoping San Mateo County should pair this aggregate view with the individual ZIP profiles to identify the densest, highest-income pockets first, then expand outward along whatever transportation corridor matches their delivery model. For a wider commuter-shed view that crosses county lines, see the San Francisco–Oakland–Berkeley metro hub.