Postal reference / United States
94546Castro Valley, California
ZIP code 94546 is a United States postal code for Castro Valley, California. Its county association is Alameda County. The map reference point is at 37.7015, -122.0782.
- State / territory
- California
- Recorded place name
- Castro Valley
- County association
- Alameda
- Estimated coordinate
- 37.7015, -122.0782
View on OpenStreetMap - ZIP prefix
- 945 · 93 ZIP codes share it
- Data source
- GeoNames postal reference, snapshot September 26, 2026
GeoNames reference data. County associations may not include every intersecting county, place names are postal names rather than legal boundaries, and coordinates are approximate. This is not address validation.
Area
- Land area
- 15.957 sq mi (2023 Census Gazetteer)
Figures are for the ZIP Code Tabulation Area (ZCTA) that most closely matches this ZIP code, not an exact match to USPS delivery boundaries. Source: U.S. Census Bureau, 2023 Gazetteer + 2023 ACS 5-Year Estimates, retrieved 2026-09-27. How to read this data.
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California directoryOther ZIP codes in Castro Valley, CA
Castro Valley has 2 ZIP codes in the reference dataset.
- 94552Alameda
Nearby ZIP code reference points
| ZIP code | Place | State | County association | Miles |
|---|---|---|---|---|
| 94541 | Hayward | CA | Alameda | 2.0 |
| 94543 | Hayward | CA | Alameda | 2.3 |
| 94552 | Castro Valley | CA | Alameda | 2.3 |
| 94578 | San Leandro | CA | Alameda | 2.5 |
| 94580 | San Lorenzo | CA | Alameda | 3.2 |
| 94542 | Hayward | CA | Alameda | 3.4 |
| 94579 | San Leandro | CA | Alameda | 4.1 |
| 94544 | Hayward | CA | Alameda | 4.5 |
Straight-line distance between reference points. Nearby points do not prove that ZIP areas touch.
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