Home > CA > San Mateo County > San Mateo > Zip 94403

Zip Code 94403 — San Mateo, CA

ZIP Code 94403 is associated with San Mateo, CA, in San Mateo County. The listed population estimate is 43,276; estimated density is 2,966.4 people per square mile. Among records with population estimates, it ranks #4 of 29 in San Mateo County and #330 of 1,762 in CA.
Page generated: 2026-10-08. This is not the source data release date.

📍 View location on OpenStreetMap (37.538440, -122.304540)

Data MetricLocal Statistic
Postal / Zip Code94403
Primary CitySan Mateo
State / ProvinceCA
CountySan Mateo
Total Population43,276
Population Density2,966.4 people/sq mi
TimezoneAmerica/Los_Angeles

How 94403 Compares

MetricZIP 94403San Mateo County recordsCA records
Population estimate43,276713,109 (sum)39,286,245 (sum)
Population Density2,966.4 /sq mi----
County population rank#4 of 29----
State population rank#330 of 1,762----

Regional sums combine the population estimates in the listed ZIP records; they are not official county or state population totals.

Explore More ZIP Codes

Nearby ZIP Codes in CA

ZIP CodeCityDistancePopulation estimate
ZIP 94402San Mateo1.6 mi25,475
ZIP 94002Belmont1.7 mi27,534
ZIP 94404San Mateo2.3 mi35,881
ZIP 94401San Mateo2.6 mi35,295
ZIP 94065Redwood City3.2 mi11,673

Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →