9th most populous of 58
With 1,172,607 residents in 2024, Contra Costa County ranks 9th by population among California's 58 counties and is home to 3.0% of the state's residents.
Contra Costa County is home to 1,172,607 people (2024 estimate) on 717 square miles of land, with Martinez as county seat. This page brings together official U.S. Census Bureau population estimates since 2000, the components of change—births, deaths and migration—and American Community Survey indicators on income, housing and employment.
Key indicators
Population
1,172,607
July 1, 2024 estimate
2020 Census base
1,165,983
April 1, 2020
Change since 2020
+0.6%
2020–2024
Land area
717 mi²
1,857 km²
Population density
1,635.7 /mi²
2024 estimate ÷ land area
Births
11,185
Year to July 1, 2024
Deaths
8,420
Year to July 1, 2024
Natural change
+2,765
Births minus deaths, 2024
Net migration
+7,594
Domestic + international, 2024
Median home value
$866,800
ACS 2020–2024 5-year
Unemployment rate
4.5%
BLS annual average, 2024
Per capita personal income
$108,259
BEA, 2024
Gross domestic product
$96.6 billion
BEA, current dollars, 2024
Median household income
$127,229
ACS 2020–2024 5-year
Poverty rate
8.4%
ACS 2020–2024 5-year
Bachelor’s degree or higher
45.2%
Age 25+, ACS 2020–2024 5-year
Foreign-born residents
26.6%
ACS 2020–2024 5-year
Historical data
Pick an indicator to see its long-run evolution.
Population
2000–20241,172,607▲ 23%
U.S. Census Bureau: intercensal estimates 2000–2009, Vintage 2020 (2010–2019) and Vintage 2024 (2020–2024), July 1.
Data summary
| Indicator | Value | Year and source |
|---|---|---|
| Population estimate | 1,172,607 | 2024 · U.S. Census Bureau |
| Population, 2010 Census | 1,049,025 | 2010 · U.S. Census Bureau |
| Population, 2000 | 952,810 | July 1, 2000 · Census intercensal |
| Change since 2000 | +23.1% | 2000–2024 · Census |
| International migration | +12,286 | 2024 · Census Vintage 2024 |
| Domestic migration | −4,692 | 2024 · Census Vintage 2024 |
| Birth rate | 9.5 per 1,000 | 2024 · calculated |
| Death rate | 7.2 per 1,000 | 2024 · calculated |
| Population rank in California | 9th of 58 | 2024 · calculated |
| Density rank in California | 7th of 58 | 2024 · calculated |
| County seat | Martinez | California State Association of Counties |
| Per capita personal income | $108,259 | BEA, 2024 · official |
| Gross domestic product | $96.6 billion | BEA, current dollars, 2024 · official |
| Median household income | $127,229 | ACS 2020–2024 5-year · official |
| Poverty rate | 8.4% | ACS 2020–2024 5-year · official |
| Bachelor’s degree or higher | 45.2% | Age 25+, ACS 2020–2024 5-year · official |
| Foreign-born residents | 26.6% | ACS 2020–2024 5-year · official |
| Median home value | $866,800 | ACS 2020–2024 5-year · official |
| Median gross rent | $2,375/month | ACS 2020–2024 5-year · official |
| Median age | 40.5 years | ACS 2020–2024 5-year · official |
| Households | 414,417 | ACS 2020–2024 5-year · official |
| Owner-occupied homes | 68.0% | ACS 2020–2024 5-year · official |
Contra Costa County in context
Comparable indicators for Contra Costa County, California and the United States.
| Indicator | County | California | U.S. | Reference |
|---|---|---|---|---|
| Population change 2020–2024 | +0.6% | −0.3% | +2.6% | Census Vintage 2024 |
| Birth rate (per 1,000) | 9.5 | 10.2 | 10.6 | 2024 |
| Death rate (per 1,000) | 7.2 | 7.4 | 9.1 | 2024 |
| Net migration rate (per 1,000) | 6.5 | 3.1 | 8.2 | 2024 |
| Population density (/mi²) | 1,635.7 | 253.0 | 96.3 | Land area, Census Gazetteer |
| Per capita personal income | $108,259 | $86,232 | $73,204 | BEA, 2024 |
| Median household income | $127,229 | $99,122 | $80,734 | ACS 2020–2024 5-year |
| Poverty rate | 8.4% | 12.0% | 12.5% | ACS 2020–2024 5-year |
| Bachelor’s degree or higher | 45.2% | 37.1% | 35.7% | Age 25+, ACS 2020–2024 5-year |
| Foreign-born residents | 26.6% | 27.0% | 14.1% | ACS 2020–2024 5-year |
| Median home value | $866,800 | $734,700 | $332,700 | ACS 2020–2024 5-year |
| Median gross rent | $2,375/month | $2,036/month | $1,413/month | ACS 2020–2024 5-year |
| Median age | 40.5 years | 37.9 years | 38.9 years | ACS 2020–2024 5-year |
| Owner-occupied homes | 68.0% | 55.9% | 65.2% | ACS 2020–2024 5-year |
Cities & towns
7 cities · choose how to order them
Did you know? Contra Costa County
A quarter century of change
Its population went from 952,810 in 2000 to 1,172,607 in 2024, a change of +23.1%, compared with +16.0% for California as a whole.
Births and deaths
In the year to July 2024 the county recorded 11,185 births and 8,420 deaths, so births outnumbered deaths by 2,765.
Peak population in 2024
Annual Census estimates since 2000 put the county's highest population at 1,172,607 in 2024.
7th in density
Contra Costa County has about 1,635.7 residents per square mile of land, ranking 7th of 58 counties; California averages 253.0.
Household income rank
With a median household income of $127,229 (ACS 2020–2024 5-year), the county ranks 6th of 58 California counties; the state median is $99,122.
Size of the economy
Its economy produced $96.6 billion of GDP in 2024 (BEA), 11th largest among 58 California counties.
Latest economic growth
Real GDP grew 1.1% in 2024, adjusted for inflation (BEA, chained 2017 dollars).
Sources and methodology
- U.S. Census Bureau — County population totals and components, Vintage 2024
- U.S. Census Bureau — County estimates 2010–2020
- U.S. Census Bureau — Intercensal estimates 2000–2010
- U.S. Census Bureau — American Community Survey 2023 5-year
- U.S. Census Bureau — Gazetteer files
- U.S. Bureau of Labor Statistics — LAUS
- U.S. Census Bureau — American Community Survey 2020–2024 5-year
- U.S. Bureau of Economic Analysis — Regional economic accounts