| ZIP Codes: | 52 ZIP Codes (38 Standard, 13 PO Box, 1 Unique) [See All] |
| Area Codes: | 341 / 369 / 510 / 707 / 925 |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 2:11:28 PM |
| Population: | 1,159,422 [See All] |
| FIPS: | 06013 |
| CBSA: | San Francisco-Oakland-Fremont, CA |
| Land Area: | 674 sq mi |
| Water Area: | 25 sq mi |
| Coordinates: | 37.9274, -122.0677 |
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1,159,422 residents live across 52 ZIPs covering 674 sq mi, served by 30 distinct USPS-recognized cities.
Population moved from 1,075,567 to 1,159,422 from 2014 to 2024 — a +7.8% change. 33 ZIPs gained residents, 9 lost.
The county's wealthiest ZIP 94506 (Danville, $250,001 median) and poorest ZIP 94511 (Bethel Island, $74,972) are 21.0 miles apart — a 3.3× income gap across local geography.
Median home values vary 3.4× across this county — from $583,800 in 94565 (Pittsburg) to $2,000,001 in 94549 (Lafayette).
Density varies 149× across the county — from 57 people/sq mi in 94514 (Byron) to 8,479 in 94805 (Richmond).
Educational attainment ranges from 16.5% bachelor's+ in 94514 (Byron) to 85.7% in 94563 (Orinda) — the breadth of educational profiles across the area.
Within California, this is the #9 most populous of 58 counties and ranks #5 for median household income with the #12 fastest decade growth .
On the national stage, Contra Costa County is the #41 most populous US county , ranks #34 for income .
Hosts 1 single-entity Unique ZIP: 94529Chevron Usa Inc .
Weighted by population, the typical household earns about $136,250 across the county — reflecting what a typical resident sees, not a simple ZIP average.
45.0% of adults age 25+ hold a bachelor's degree or higher (365,784 of 811,964 reporting).
38 Standard delivery, 13 PO Box only, 1 single-entity Unique ZIPs serve this county.
14 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.
Median household income spans 3.3× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 94565 | Pittsburg | Standard | 100,488 | $95,556 | 41.1 | 15.0% |
| 94509 | Antioch | Standard | 70,090 | $86,196 | 20.5 | 10.6% |
| 94513 | Brentwood | Standard | 69,755 | $142,223 | 99.9 | 22.5% |
| 94806 | San Pablo | Standard | 62,546 | $86,034 | 9.2 | 4.1% |
| 94553 | Martinez | Standard | 48,643 | $124,130 | 66.5 | -0.5% |
| 94582 | San Ramon | Standard | 47,424 | $214,677 | 11.6 | 19.4% |
| 94531 | Antioch | Standard | 46,387 | $120,927 | 16.6 | 8.9% |
| 94561 | Oakley | Standard | 46,368 | $134,678 | 25.1 | 20.5% |
| 94804 | Richmond | Standard | 44,891 | $91,037 | 6.4 | 9.6% |
| 94521 | Concord | Standard | 41,909 | $125,899 | 11.8 | 1.9% |
| 94583 | San Ramon | Standard | 39,583 | $184,898 | 22.1 | 12.2% |
| 94520 | Concord | Standard | 37,381 | $82,479 | 15.4 | -3.5% |
| 94523 | Pleasant Hill | Standard | 34,592 | $142,586 | 7.3 | 0.5% |
| 94801 | Richmond | Standard | 33,591 | $81,728 | 9.5 | 14.8% |
| 94526 | Danville | Standard | 32,584 | $225,097 | 13.4 | 1.0% |
| 94549 | Lafayette | Standard | 28,420 | $234,516 | 20.2 | 0.4% |
| 94803 | El Sobrante | Standard | 27,659 | $118,447 | 17.1 | 6.4% |
| 94518 | Concord | Standard | 27,345 | $112,094 | 5.1 | 2.6% |
| 94598 | Walnut Creek | Standard | 27,206 | $186,225 | 24.4 | 0.9% |
| 94506 | Danville | Standard | 27,055 | $250,001 | 15.7 | 23.6% |
| 94530 | El Cerrito | Standard | 26,401 | $128,529 | 4.4 | 8.6% |
| 94547 | Hercules | Standard | 26,302 | $129,397 | 5.7 | 6.8% |
| 94596 | Walnut Creek | Standard | 23,417 | $135,635 | 6.1 | 12.7% |
| 94597 | Walnut Creek | Standard | 23,129 | $132,063 | 4.0 | 12.0% |
| 94563 | Orinda | Standard | 19,378 | $250,001 | 20.4 | 6.0% |
| 94519 | Concord | Standard | 19,058 | $122,418 | 6.2 | -4.4% |
| 94564 | Pinole | Standard | 18,761 | $127,717 | 5.8 | 0.3% |
| 94595 | Walnut Creek | Standard | 16,988 | $100,552 | 5.2 | 0.9% |
| 94556 | Moraga | Standard | 15,998 | $215,720 | 20.1 | 3.2% |
| 94505 | Discovery Bay | Standard | 14,970 | $146,480 | 22.0 | 4.3% |
| 94805 | Richmond | Standard | 14,670 | $111,152 | 1.7 | 2.4% |
| 94507 | Alamo | Standard | 14,586 | $250,001 | 9.9 | -8.7% |
| 94517 | Clayton | Standard | 12,316 | $168,921 | 48.8 | -3.6% |
| 94572 | Rodeo | Standard | 8,976 | $91,484 | 4.3 | -7.0% |
| 94525 | Crockett | Standard | 3,372 | $110,899 | 2.7 | 7.0% |
| 94514 | Byron | Standard | 1,953 | $76,511 | 34.3 | 66.4% |
| 94511 | Bethel Island | PO Box | 1,864 | $74,972 | 7.3 | -13.6% |
| 94528 | Diablo | PO Box | 1,049 | $207,500 | 1.1 | 14.6% |
| 94575 | Moraga | Standard | 975 | — | 0.0 | -23.5% |
| 94548 | Knightsen | PO Box | 832 | $189,653 | 0.3 | 108.0% |
| 94569 | Port Costa | PO Box | 296 | $38,929 | 2.5 | -7.5% |
| 94516 | Canyon | PO Box | 214 | $113,333 | 2.1 | 39.0% |
| 94570 | Moraga | PO Box | — | — | 0.0 | — |
| 94850 | Richmond | Standard | — | — | 0.0 | — |
| 94529 | Concord | Unique | — | — | 0.0 | — |
| 94527 | Concord | PO Box | — | — | 0.0 | — |
| 94524 | Concord | PO Box | — | — | 0.0 | — |
| 94522 | Concord | PO Box | — | — | 0.0 | — |
| 94820 | El Sobrante | PO Box | — | — | 0.0 | — |
| 94807 | Richmond | PO Box | — | — | 0.0 | — |
| 94802 | Richmond | PO Box | — | — | 0.0 | — |
| 94808 | Richmond | PO Box | — | — | 0.0 | — |