| ZIP Codes: | 37 ZIP Codes (28 Standard, 8 PO Box, 1 Unique) [See All] |
| Area Codes: | 415 / 628 / 650 |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 2:11:30 PM |
| Population: | 713,109 [See All] |
| FIPS: | 06081 |
| CBSA: | San Francisco-Oakland-Fremont, CA |
| Land Area: | 469 sq mi |
| Water Area: | 7 sq mi |
| Coordinates: | 37.5215, -122.3432 |
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713,109 residents live across 37 ZIPs covering 469 sq mi, served by 23 distinct USPS-recognized cities.
Population moved from 711,107 to 709,275 from 2014 to 2024 — a -0.3% change. 15 ZIPs gained residents, 14 lost.
The county's wealthiest ZIP 94027 (Atherton, $250,001 median) and poorest ZIP 94038 (Moss Beach, $99,680) are 17.2 miles apart — a 2.5× income gap across local geography.
Median home values vary 2.0× across this county — from $995,900 in 94020 (La Honda) to $2,000,001 in 94010 (Burlingame).
Density varies 703× across the county — from 16 people/sq mi in 94060 (Pescadero) to 11,435 in 94401 (San Mateo).
Educational attainment ranges from 34.1% bachelor's+ in 94060 (Pescadero) to 83.2% in 94027 (Atherton) — the breadth of educational profiles across the area.
Within California, this is the #15 most populous of 58 counties and ranks #1 for median household income .
On the national stage, San Mateo County is the #95 most populous US county , ranks #3 for income .
Hosts 1 single-entity Unique ZIP: 94497Postal Data Center .
Weighted by population, the typical household earns about $166,240 across the county — reflecting what a typical resident sees, not a simple ZIP average.
54.7% of adults age 25+ hold a bachelor's degree or higher (286,016 of 522,717 reporting).
28 Standard delivery, 8 PO Box only, 1 single-entity Unique ZIPs serve this county.
13 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 94080 | South San Francisco | Standard | 64,761 | $136,733 | 10.1 | -1.9% |
| 94015 | Daly City | Standard | 64,091 | $127,056 | 5.7 | 1.8% |
| 94014 | Daly City | Standard | 45,315 | $122,966 | 5.3 | -6.6% |
| 94403 | San Mateo | Standard | 43,276 | $174,917 | 5.8 | 8.1% |
| 94010 | Burlingame | Standard | 43,025 | $196,882 | 19.7 | 1.9% |
| 94066 | San Bruno | Standard | 42,728 | $141,272 | 6.1 | 1.5% |
| 94025 | Menlo Park | Standard | 40,721 | $216,601 | 11.6 | -0.5% |
| 94044 | Pacifica | Standard | 37,274 | $160,408 | 14.9 | -3.0% |
| 94061 | Redwood City | Standard | 37,048 | $146,265 | 3.9 | -1.6% |
| 94404 | San Mateo | Standard | 35,881 | $192,332 | 5.0 | 2.4% |
| 94401 | San Mateo | Standard | 35,295 | $122,227 | 3.1 | -4.2% |
| 94063 | Redwood City | Standard | 34,433 | $116,760 | 11.7 | 8.0% |
| 94070 | San Carlos | Standard | 30,447 | $240,074 | 6.4 | 1.9% |
| 94002 | Belmont | Standard | 27,534 | $203,965 | 8.5 | 3.2% |
| 94062 | Redwood City | Standard | 25,759 | $233,262 | 58.3 | -4.6% |
| 94402 | San Mateo | Standard | 25,475 | $172,522 | 5.0 | 4.8% |
| 94030 | Millbrae | Standard | 22,689 | $163,476 | 9.8 | 2.2% |
| 94019 | Half Moon Bay | Standard | 14,419 | $153,781 | 71.5 | -21.6% |
| 94065 | Redwood City | Standard | 11,673 | $215,955 | 6.1 | 0.8% |
| 94027 | Atherton | Standard | 7,002 | $250,001 | 5.4 | -3.2% |
| 94028 | Portola Valley | Standard | 6,531 | $250,001 | 19.1 | -2.8% |
| 94005 | Brisbane | Standard | 4,692 | $156,169 | 5.9 | 6.1% |
| 94018 | El Granada | PO Box | 3,834 | $230,053 | 0.5 | — |
| 94037 | Montara | PO Box | 2,917 | $233,826 | 6.2 | 1.3% |
| 94038 | Moss Beach | Standard | 2,683 | $99,680 | 1.7 | -21.9% |
| 94020 | La Honda | Standard | 1,694 | $250,001 | 33.0 | 14.2% |
| 94060 | Pescadero | Standard | 1,465 | $127,973 | 90.1 | -11.2% |
| 94021 | Loma Mar | Standard | 321 | $250,001 | 12.6 | 52.1% |
| 94074 | San Gregorio | Standard | 126 | $250,001 | 22.6 | -60.6% |
| 94128 | San Francisco | Standard | 0 | — | 3.6 | -100.0% |
| 94083 | South San Francisco | PO Box | — | — | 0.0 | — |
| 94497 | San Mateo | Unique | — | — | 0.0 | — |
| 94011 | Burlingame | PO Box | — | — | 0.0 | — |
| 94026 | Menlo Park | PO Box | — | — | 0.0 | — |
| 94064 | Redwood City | PO Box | — | — | 0.0 | — |
| 94017 | Daly City | PO Box | — | — | 0.0 | — |
| 94016 | Daly City | PO Box | — | — | 0.0 | — |