Contra Costa County Population

1860–2026

1.17M

2026 projection

0.4% since 2020 (increase)

00.2M0.4M0.6M0.8M1M1.2M186018801900192019401960198020002020

Source: U.S. Census Bureau decennial counts and annual estimates. 2026 is a projection. Values between recorded years are interpolated.

Use the left and right arrow keys to inspect population observations.

Population by year

Population estimates for Contra Costa County. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
20261,170,606+5360.05%
20251,170,070+5360.05%
20241,169,534+7,5810.65%
20231,161,953+1,7900.15%
20221,160,163-4,2070.36%
20211,164,370-1,8790.16%
20201,166,249+13,3661.16%
20191,152,883+2,0430.18%
20181,150,840+5,2170.46%
20171,145,623+8,3640.74%

Showing 10 of 31 years.

Contra Costa County Demographics

40.5median age

Median age

Female41.5 yrs
Male39.5 yrs

Adults

909,012
199,270 seniors (65+) · 22% of adults709,742 other adults

Sex

Female 50.8% · 592,046Male 49.2% · 572,966

Population by age

MaleFemale85+ years, male: 8,20285+ years, female: 14,88280–84 years, male: 10,15680–84 years, female: 12,63675–79 years, male: 16,97175–79 years, female: 20,71270–74 years, male: 24,83870–74 years, female: 28,88665–69 years, male: 28,87465–69 years, female: 33,11360–64 years, male: 35,86460–64 years, female: 38,69555–59 years, male: 38,87955–59 years, female: 38,50850–54 years, male: 39,77650–54 years, female: 39,90045–49 years, male: 38,60845–49 years, female: 39,65240–44 years, male: 40,39140–44 years, female: 42,39035–39 years, male: 41,40035–39 years, female: 40,71630–34 years, male: 37,29130–34 years, female: 37,78625–29 years, male: 33,86725–29 years, female: 33,15920–24 years, male: 33,23320–24 years, female: 32,50115–19 years, male: 38,88815–19 years, female: 36,70410–14 years, male: 40,10010–14 years, female: 36,8635–9 years, male: 33,9715–9 years, female: 34,6760–4 years, male: 31,6570–4 years, female: 30,26785+80–8475–7970–7465–6960–6455–5950–5445–4940–4435–3930–3425–2920–2415–1910–145–90–420K20K

Hover or tap an age group to see exact counts. Use the up and down arrow keys to inspect age groups.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101

Race and ethnicity

Tap a square or a group below to highlight it.

Each square is about 1% of residents (roughly 11,650 people).

Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002

Contra Costa County Income

$127,229median household income

Median household income

$127,229

Half of households earn more, half earn less

Median earnings

$71,603

Typical yearly pay for a worker 25 or older.

Poverty rate

8.4%

About 1 in 12 residents

U.S. Census Bureau, 2024 ACS 5-year estimates · Tables S1901, S1501, S1701

Contra Costa County Marital Status

52% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married52%54%50%
Never married33%36%31%
Divorced9%7%11%
Widowed5%2%7%
Separated2%1%2%

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201

Sources

8 sources, all from the U.S. Census Bureau

Population

American Community Survey, 2024 5-year