Contra Costa County, California Demographics 2026

Population Overview

Contra Costa County is located in California with a total population of 1,161,458. It is the 9th most populous county out of 58 in California.

Age Demographics

The median age in Contra Costa County is 40.3 years. This is 7% higher than the state median of 37.6 years.

Economy, Income & Housing

The median household income in Contra Costa County is $125,727. This is 31% higher than the state median of $96,334. Compared to the national median of $78,538, household income here is 60% higher. The poverty rate stands at 8.3%. This is 31% lower than the state poverty rate of 12.0%. The unemployment rate is 5.9%. This is 8% lower than the state rate of 6.4%. The median home value is $830,800. Housing costs are 19% higher than the state median of $695,400. The home-value-to-income ratio of 6.6x suggests that housing affordability is a significant concern for many residents. 67.7% of occupied housing units are owner-occupied. This homeownership rate is 21% higher than the state average of 55.8%.

Race & Ethnicity

Contra Costa County is a highly diverse community where no single racial or ethnic group constitutes a majority of the population. Hispanic or Latino residents account for 27.3%. The Black or African American population is significantly higher than the state average (8.2% vs 5.3%).

Education

44.9% of residents aged 25 and older hold a bachelor's degree or higher. This places Contra Costa County in the top 10% of all cities in the state for educational attainment. This is 23% higher than the state rate of 36.5%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 89.6%. Notably, 17.5% of adults hold a graduate or professional degree, indicating a highly educated workforce.