Demographics

Contra Costa County Demographic Quick Facts

2020 Decennial Census Results 

On August 12, 2021 the Census Bureau released the first local level 2020 Census data. Initial analysis is provided below. The State Department of Finance has additional detailed tables available.
Visit the State Department of Finance Census 2020 webpage.
Data Profile for all Cities, Towns, and Unincorporated Census Designated Places (PDF)

2020 County Population: 1,165,927

Contra Costa County saw an increase of 116,902 people (10% increase)
Source: 2020 Decennial Census

2020 Population by Supervisorial District

During the once a decade redistricting process, districts must be redrawn so that each district is substantially equal in population. In California, Redistricting must be done using the California Redistricting data, which is based on the 2020 Census data. 
Equal Proportion based on 2020 Census: 233,185 people.Supervisorial District Population Growth Chart showing population growth by Supervisorial District.
The current spread is 8.08%, this is the difference between the highest and lowest percentage from the mean.
The percentage deviation from the mean is shown in parenthesis below. 

District 1 Population: 224,726
8,459 under (-3.63%)

District 2 Population: 243,565
10,380 over (4.45%)

District 3 Population: 239,825
6,640 over (2.85%)

District 4 Population: 229,384
3,837 under (-1.65%)

District 5 Population: 228,463
4,722 under (-2.03%)

2020 City Population and Growth Rate

City2020 Population2010 PopulationGrowth Rate
Brentwood city                          64,292                          51,48119.9%
Oakley city                          43,357                          35,43218.3%
Pittsburg city                          76,416                          63,26417.2%
San Ramon city                          84,605                          72,14814.7%
Antioch city                        115,291                        102,37211.2%
Richmond city                        116,448                        103,70110.9%
Orinda city                          19,514                          17,6439.6%
San Pablo city                          32,127                          29,1399.3%
El Cerrito city                          25,962                          23,5499.3%
Walnut Creek city                          70,127                          64,1738.5%
Hercules city                          26,016                          24,0607.5%
Lafayette city                          25,391                          23,8935.9%
Moraga town                          16,870                          16,0165.1%
Pleasant Hill city                          34,613                          33,1524.2%
Martinez city                          37,287                          35,8243.9%
Danville town                          43,582                          42,0393.5%
Pinole city                          19,022                          18,3903.3%
Concord city                        125,410                        122,0672.7%
Clayton city                          11,070                          10,8971.6%

2010 Population: 1,049,025

source: 2010 Decennial Census

2020 Countywide Population Estimate: 1,153,561
2020 Unincorporated County Population Estimate: 174,257

Source: California Department of Finance Demographic Research Unit

Explore Department of Finance Population Estimates for Cities, County, and the State

Population Characteristic Data

The Census Bureau's American Community Survey (ACS) provides detailed information about population characteristics. Explore Census ACS Data at data.census.gov
Learn More About ACS data - US Census Bureau's ACS Users Guide

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