Contra Costa County, CA Population

Overview

1.16 million

Total Population

39.9

Median age

50.84%

Female population %

96.7:100

Gender ratio (M:F)

55-59 years

Largest age group

52.4

Total dependency ratio

White

Largest racial group

304,321

Hispanic population

Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

TABLE OF CONTENTS

Age

Contra Costa County's population is old compared to the rest of the country:

The median age in Contra Costa County is 39.9, compared to 38.8 nationwide, according to the American Community Survey 2017 - 2021 5 Year estimates.
Contra Costa County's population under 18 was 22.68%, compared to the 22.51% nationwide.
Contra Costa County's elderly or the senior population (over 65 age) was 15.84% as compared to 16.04% nationwide.
Of the total population in Contra Costa County, 18.52% were under the age of 15, 18.27% aged 15 to 29, 47.36% aged 30 to 64, 13.95% aged 65 to 84, and 1.89% were 85 years of age and older.

There are 19,631 more females than males in Contra Costa County:

The female percentage in the USA is 50.50% while the male percentage is 49.50%, compared to 50.84% females and 49.16% males in Contra Costa County, CA.
The Contra Costa County, CA gender ratio is 96.7:100 i.e. 96.7 men to 100 women (0.967).
For male population, the largest age group is 10-14 years with a population of 40,614.
For the female population, the largest age group is 55-59 years with a population of 41,837.

Contra Costa County's population has become increasingly diverse:

Racial distribution of Contra Costa County population: 49.97% are White, 8.63% are Black or African American, 0.67% are American Indian and Alaska Native, 17.81% are Asian, 0.48% are Native Hawaiian and other Pacific Islander, 11.73% are some other race and 10.70% are multiracial.
Contra Costa County's racial breakdown clearly shows that there is no majority of any race in the county.
By ethnicity, 304,321 is Hispanic or Latino (of any race), and 857,322 (73.80% of the total population) is Non-Hispanic.
The largest racial group in Contra Costa County is White with a population of 580,523 (49.97% of the total population).

Contra Costa County's population has already reached its peak and is showing a trend of decline:

The peak population was 1,165,986 in the year 2020
From 2000 to 2010, Contra Costa County's population increased by 99,392 (10.43%), as compared to the national growth of 9.63%.
From 2010 to 2020, Contra Costa County's population increased by 113,470 (10.78%), according to Census Bureau's Population Estimates Program. For the same period, the rate of growth for the United States was 7.17%.
Between the year 2000 and 2022, Contra Costa County's population was lowest in year 2000 at 953,124.