Alameda County, CA: Cities, ZIP Codes & Population
Alameda County is a county-level area in California identified by the FIPS code 06001. Our data lists 20 places in it, led by Oakland, CA, with combined estimates of about 1,665,305 people across those places. This page shows its cities, ZIP codes, time zone and neighboring counties.
What are the key facts about Alameda County?
| County | Alameda County |
|---|---|
| State | California |
| FIPS code | 06001 |
| Places in our data | 20 |
| Places with a city page | 19 |
| Combined place estimates | 1,665,305 |
| Largest place | Oakland, CA (433,031) |
| Rank in state | 10th of 58 counties by combined place population |
| Weighted density | 6,009 per sq mi |
| Time zone | Pacific time |
| ZIP codes | 69 |
Which cities and towns are in Alameda County?
Alameda County has 19 places large enough for a full page on this site. They are ranked below by estimated population, together with whether each is incorporated, its density in people per square mile and the number of ZIP codes it uses. Oakland, CA is the largest, followed by Fremont, CA.
| Place | Type | Population | Per sq mi | ZIPs |
|---|---|---|---|---|
| Oakland, CA | Incorporated | 433,031 | 7,747 | 29 |
| Fremont, CA | Incorporated | 241,110 | 3,111 | 5 |
| Hayward, CA | Incorporated | 159,203 | 3,494 | 7 |
| Berkeley, CA | Incorporated | 121,363 | 11,585 | 11 |
| Livermore, CA | Incorporated | 90,923 | 3,336 | 2 |
| San Leandro, CA | Incorporated | 88,815 | 6,656 | 4 |
| Pleasanton, CA | Incorporated | 81,777 | 3,385 | 2 |
| Alameda, CA | Incorporated | 77,624 | 7,428 | 2 |
| Union City, CA | Incorporated | 74,107 | 3,818 | 1 |
| Dublin, CA | Incorporated | 64,826 | 4,255 | 2 |
| Castro Valley, CA | Unincorporated / CDP | 63,013 | 3,797 | 3 |
| Newark, CA | Incorporated | 49,149 | 3,541 | 1 |
| San Lorenzo, CA | Unincorporated / CDP | 25,569 | 9,213 | 2 |
| Ashland, CA | Unincorporated / CDP | 24,430 | 13,292 | 3 |
| Albany, CA | Incorporated | 19,696 | 11,007 | 1 |
| Cherryland, CA | Unincorporated / CDP | 16,066 | 13,406 | 1 |
| Emeryville, CA | Incorporated | 12,086 | 9,518 | 2 |
| Piedmont, CA | Incorporated | 11,135 | 6,550 | 2 |
| Fairview, CA | Unincorporated / CDP | 10,532 | 3,828 | 2 |
The county also contains 1 smaller community that appear here but do not have separate pages because their populations are too small for reliable data: Sunol. Residents of these places often depend on the county for services such as roads, courts and public health.
How large is Alameda County compared with other counties in California?
Adding up the estimates for the places in our data gives 1,665,305 people, which ranks Alameda County 10th among 58 counties in California. The average listed place has about 83,265 residents. The weighted density is about 6,009 people per square mile, which is an urban core by our scale. These totals add up place estimates, so they can differ from the official county population, which includes people outside any listed place. See why population figures differ.
What ZIP codes are in Alameda County?
The places in Alameda County use 69 ZIP codes: 94501, 94502, 94536, 94537, 94538, 94539, 94540, 94541, 94542, 94543, 94544, 94545, 94546, 94550, 94551, 94552, 94555, 94557, 94560, 94566, 94568, 94577, 94578, 94579, 94580, 94586, 94587, 94588, 94601, 94602, 94603, 94604, 94605, 94606, 94607, 94608, 94609, 94610, 94611, 94612, 94613, 94614, 94615, 94617, 94618, 94619, 94620, 94621, 94622, 94623, 94624, 94649, 94659, 94660, 94661, 94662, 94666, 94701, 94702, 94703 and 9 more. Every code begins with 9, which is assigned to the Pacific states (Alaska, California, Hawaii, Oregon and Washington). A ZIP code can cross county lines, so a code listed here may also serve addresses in a neighboring county. Use the ZIP code lookup to check a single code, or read how ZIP codes work.
Which counties are near Alameda County?
The closest counties by distance between the average locations of their places are listed below. The distance is a rough guide to how close the areas are, because county shapes vary widely.
- Contra Costa County, CA — about 16 miles north (center to center), 1,836,522 people in listed places
- San Mateo County, CA — about 19 miles southwest (center to center), 756,053 people in listed places
- San Francisco County, CA — about 20 miles west (center to center), 3,592,294 people in listed places
- Santa Clara County, CA — about 29 miles south (center to center), 2,732,982 people in listed places
- Marin County, CA — about 34 miles northwest (center to center), 241,205 people in listed places
- Solano County, CA — about 41 miles north (center to center), 517,871 people in listed places
What does the FIPS code 06001 mean?
The first two digits, 06, identify California, and the last three, 001, identify Alameda County inside that state. Government datasets use this code to join records without confusing counties that share a name. Our guide to counties and FIPS codes explains the numbering, and the California hub lists every county we cover in the state.
Where to go next
Combined place populations are estimates from a compiled dataset and are not official county totals.