Skip to content

Demographics of Contra Costa County, California

Contra Costa County, California had 1,170,070 people on July 1, 2025, by the Census Bureau’s estimate: +3,821 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

Contra Costa County, in four figures

1,170,070
Population
July 1, 2025, Vintage 2025 estimate.
+0.3%
Change since July 2020
+3,821 people.
40.5 ±0.1
Median age
ACS 2020–⁠2024.
$127,229 ±$1,713
Median household income
ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

Contra Costa County, California's population grew 0.3% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Contra Costa County, California's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

Contra Costa County, California's population grew 0.3% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Contra Costa County, California's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1PopulationIndexUnited States
20201,166,249100.0100.0
20211,164,37099.8100.2
20221,160,16399.5100.7
20231,161,95399.6101.6
20241,169,534100.3102.5
20251,170,070100.3103.1

3 more columns on a wider screen

Population of Contra Costa County, California on July 1 of each year, Vintage 2025
July 1PopulationChange
20201,166,249+214
20211,164,370−1,879
20221,160,163−4,207
20231,161,953+1,790
20241,169,534+7,581
20251,170,070+536

Age, 2020–2024

The median age is 40.5 ±0.1: for men 39.5 ±0.2 and for women 41.5 ±0.2. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

2 more columns on a wider screen

People in Contra Costa County by age, ACS 2020–2024
AgePeopleShare
Under 561,924 ±1285.3% ±<0.1
5 to 17194,076 ±2,32416.7% ±0.2
18 to 2492,860 ±1,8598.0% ±0.2
25 to 44307,000 ±2,53526.4% ±0.2
45 to 64309,882 ±2,82326.6% ±0.2
65 and over199,270 ±2,70617.1% ±0.2

Income and poverty, 2020–2024

Median household income is $127,229 ±$1,713, and income per person $62,927 ±$732, in 2024 dollars. The median is $99,122 ±$310 in California and $80,734 ±$166 in the United States.

Households by income

2 more columns on a wider screen

Households in Contra Costa County by income, ACS 2020–2024
Household incomeHouseholdsShare
Under $25,00036,194 ±1,6698.7% ±0.4
$25,000 to $49,99941,129 ±1,9269.9% ±0.5
$50,000 to $74,99944,878 ±1,61210.8% ±0.4
$75,000 to $99,99942,542 ±1,67810.3% ±0.4
$100,000 to $149,99972,298 ±1,93317.4% ±0.5
$150,000 to $199,99955,549 ±2,02213.4% ±0.5
$200,000 or more121,827 ±2,06029.4% ±0.5

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

2 more columns on a wider screen

Poverty rate in Contra Costa County by age, ACS 2020–2024
AgeBelow povertyRate
All ages96,639 ±4,6708.4% ±0.4
Under 1825,341 ±1,66510.0% ±0.6
18 to 5950,773 ±2,6088.0% ±0.4
60 and over20,525 ±1,3837.6% ±0.5

Housing, 2020–2024

1 more column on a wider screen

Housing in Contra Costa County, ACS 2020–2024
MeasureContra Costa CountyCalifornia
Housing units429,260 ±16314,644,735 ±1,665
Occupied96.5% ±0.392.5% ±0.1
Vacant3.5% ±0.37.5% ±0.1
Owner occupied68.0% ±0.555.9% ±0.3
Renter occupied32.0% ±0.544.1% ±0.2
Median home value$866,800 ±$6,426$734,700 ±$1,307
Median gross rent$2,375 ±$22$2,036 ±$5
Median year built1978 ±11976 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

2 more columns on a wider screen

People in Contra Costa County by Hispanic origin and race, ACS 2020–2024
OriginPeopleShare
Hispanic or Latino321,749 ±027.6% ±<0.1
White alone, not Hispanic443,990 ±1,87638.1% ±0.2
Black alone, not Hispanic92,564 ±1,6397.9% ±0.1
Asian alone, not Hispanic217,115 ±2,36418.6% ±0.2
American Indian and Alaska Native alone, not Hispanic1,832 ±4150.2% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic5,283 ±4740.5% ±<0.1
Some other race alone, not Hispanic8,868 ±1,3490.8% ±0.1
Two or more races, not Hispanic73,611 ±3,5046.3% ±0.3

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

2 more columns on a wider screen

People in Contra Costa County by place of birth and citizenship, ACS 2020–2024
BornPeopleShare
Born in the state649,628 ±5,13255.8% ±0.4
Born in another state184,511 ±3,36615.8% ±0.3
Born a citizen outside the states21,262 ±1,7161.8% ±0.1
Born abroad309,611 ±4,32726.6% ±0.4
Naturalized citizens181,358 ±3,28715.6% ±0.3
Not citizens128,253 ±3,77311.0% ±0.3

Contra Costa County among the counties of California

9th of 58 by population, July 2025. Every one is listed on the California page.

Counties of California near Contra Costa County in population, July 2025
CountyJuly 2025Change since 2020
Riverside County2,544,916+5.0%
San Bernardino County2,224,091+1.9%
Santa Clara County1,914,391−0.9%
Alameda County1,636,630−2.6%
Sacramento County1,618,460+2.0%
Contra Costa County1,170,070+0.3%
Fresno County1,035,456+2.6%
Kern County927,068+2.3%
Ventura County830,851−1.5%
San Francisco County826,079−5.6%
San Joaquin County823,815+5.5%

Elsewhere on the site

Sources

Data retrieved