2020 Census Data

Data and products for California from the 2020 Census. The California State Data Center generates reports and tabulations from data files released by the U.S. Census Bureau.

Detailed Demographic and Housing Characteristics A and B Files

The 2020 Census Detailed Demographic and Housing Characteristics File A (Detailed DHC-A) along with the Detailed DHC-B files are the successors to the 2010 Census Summary File 2 and the 2010 Census American Indian and Alaska Native Summary File. The Detailed DHC-A and B files contain statistics for 300 detailed racial and ethnic groups and 1,187 American Indian and Alaska Native (AIAN) tribes and villages. The files also tabulate for regional race and ethnic groups, which were not provided in prior decennial censuses. They include groups such as Caribbean, East Asian, American Indian, and Polynesian.

Unlike prior 2020 Census data products where exact levels of accuracy cannot be known in advance, margins of error for counts are determined in advance of running the algorithm. The Census Bureau set accuracy targets for each count in the Detailed DHC-A and B to ensure that the published counts are within a target margin of error about 95 percent of the time. More information on MOEs as well as guidance on custom aggregations and comparisons to previous decennial censuses and the American Community Survey, a list of detailed race and regional groups, and a 2010 to 2020 Census race and ethnicity crosswalk can be found on the Census Bureau’s DHC-A and B technical documentation page.

Note that the Census Bureau does not recommend using the Detailed DHC-A and B files to calculate average household size due to the fact that the Detailed DHC-A includes persons in group quarters. This statistic is available in the 2020 Census Supplemental Demographic and Housing Characteristics File (S-DHC) that was released in September 2024.

Supplemental Demographic and Housing Characteristics File

The S-DHC file combines the characteristics of households and the people living in them. Data is available for the nation, all 50 states, the District of Columbia and Puerto Rico. The release consists of eight subject tables, six of which contain nine iterations by race and Hispanic origin, for a total of 62 tables:

  • PH1 – Average household size by age.*
  • PH2 – Household type (e.g., family or nonfamily households) for the population in households.
  • PH3 – Population under the age of 18 years by relationship and household type.*
  • PH4 – Population in families by age.*
  • PH5 – Average family size by age.*
  • PH6 – Family type and age for own children under the age of 18 years.
  • PH7 – Total population in occupied housing units by tenure (i.e., whether the home is owned or rented).*
  • PH8 – Average household size of occupied housing units by tenure.*

* Tables marked with an asterisk include tabulations for the following race and Hispanic origin groups: White alone, Black or African American alone, American Indian and Alaska Native alone, Asian alone, Native Hawaiian and Other Pacific Islander alone, Some Other Race alone, Two or More Races, Hispanic or Latino, and White alone, not Hispanic or Latino.

Tabulations are generated using a variant of the disclosure avoidance methodology employed for all 2020 Census data releases. Unlike the person and housing tables released previously, which were subject to separate runs of the disclosure avoidance algorithm, the S-DHC tabulations require joining the person and household data together and running the disclosure avoidance algorithm on the combined data. PHSafe, the algorithm that protects the S-DHC, works by applying truncation rules to protect outliers in the data (specifically very large households), and adding or subtracting noise to the tabulated results based on predetermined accuracy targets.

The noise-infused results undergo statistical postprocessing which ensures the data meet a series of logical constraints, such as eliminating negative values that were introduced by noise infusion. The postprocessing method also generates the credible interval for each statistic. Credible intervals represent a range of values that contain the truncated estimate with 90 percent probability. (The true value can be larger than the interval’s high value given household truncation.) Note that the intervals may not be uniform, and therefore both the lower and upper end points are published.

For more information on the PHSafe Algorithm, see Disclosure Avoidance and the Supplemental Demographic and Housing Characteristics File (S-DHC): How PHSafe Works.

Users should note inconsistencies associated with the data in the S-DHC, which result from the independent inclusion of noise into the statistics. The Census Bureau cautions that counts from S-DHC tables will not be consistent with counts from other 2020 Census data products, nor will they be consistent across S-DHC tables. The Bureau recommends:

  • Use “total population in occupied housing units” from table PH7 instead of “total population in households” from table PH2 when possible because it has less noise.
  • When the average household size does not match across tables, use data with the narrowest credible interval or data in the table most closely related to your subject of interest.

The Census Bureau also recommends using caution when aggregating the S-DHC data across custom groups or geographies. Aggregations of the S-DHC data get noisier in proportion to the number of counts that are included in the aggregation.

More information on the S-DHC can be found at Blog: Understanding the Supplemental DHC File, and by downloading the 2020 Supplemental Demographic and Housing Characteristics File (S-DHC) Technical Documentation.

Because the S-DHC only provides statistics for nation and state geographies, information on estimating people per household ratios for sub-state geographies using 2020 Census data from the Demographic and Housing Characteristics File can be found at the Census Bureau’s Calculating and Interpreting Average Household Size Ratios in the Demographic and Housing Characteristics File blog.

2020 Census S-DHC Average Household Size and Counts of People Living in Certain Types of Households Tabulation

Detailed Demographic and Housing Characteristics B File

The Detailed DHC-B file contains occupied housing unit counts broken out by tenure (owned or rented) and household type (family or non-family household) for the nation, states, counties, places, tracts, and AIAN areas. The Detailed DHC-B includes data for the household population only. Group quarters (such as college dormitories, prisons or military barracks) are excluded from this data product.

The Detailed DHC-B file also employs adaptive design to protect individualsí confidential responses. Detailed DHC-B publishes statistics using predetermined thresholds based on total population counts from the Detailed DHC-A. For example, if a group for a particular geography did not meet the threshold for publication in the Detailed DHC-A, data will not be published in the Detailed DHC-B. Note however it is possible that a group may not have a count in the Detailed DHC-A but have data in the Detailed DHC-B (and vice versa). This is because the adaptive design algorithm used to generate the Detailed DHC-B statistics first looks at the Detailed DHC-A noisy total population counts generated initially but were subsequently suppressed prior to publication.

Detailed DHC-B Population Thresholds1 and Margins of Error (MOE) by Geography

Most Comprehensive Table Type Produced Detailed Groups Regional Groups
Household Type Tenure
Nation & state
(MOE=3)		 Substate* & AIANNH
(MOE=11)		 Nation & state
(MOE=50)		 Substate*
(MOE=50)
Total Count Only Total Count Only 0-470 22-970 0-4,970 94-4,970
Household Type – 2 categories Tenure – 3 categories 471-970 971-4,970 4,971-19,970 4,971-19,970
Household Type – 6 categories Tenure – 3 categories 971-6,970 4,971-19,970 19,971-149,970 19,971-149,970
Household Type – 8 categories Tenure – 3 categories 6,971+ 19,971+ 149,971+ 149,971+

1The Detailed DHC-B uses the Detailed DHC-A noise-infused population counts that are compared to the Detailed DHC-B population thresholds to determine which, if any, household type and tenure tables the detailed or regional group is eligible to receive.

*Substate includes county, census tract, and place.

The Margins of Error (MOEs) listed apply to the individual noise-infused counts in each table type. For example, in the Household Type – 2 Categories table, two counts are noise-infused (family households and nonfamily households) and, therefore, have a MOE of 3 for detailed groups at the national and state level; however, the total number of households in this table is aggregated from the noise-infused household type counts. As a result the noise is also aggregated which results in larger MOEs for totals. For the Aggregated MOEs, please see the Detailed DHC-B technical documentation.

2020 Detailed DHC-B detailed race, regional group, and Hispanic occupied housing unit and tenure tables by geography

DRU-generated extractions of occupied housing unit and tenure tables for California, California counties, and the top six California places ranked by population. These extracts are organized by regional and detailed groups by major race and Hispanic origin.



Census Bureau published household type and tenure tables for all available races and Hispanic origins for California, California counties, and California places accessed through data.census.gov.


Detailed Demographic and Housing Characteristics A File

The 2020 Census Detailed Demographic and Housing Characteristics File A (Detailed DHC-A) along with the Detailed DHC-B (release September 2024) are the successors to the 2010 Census Summary File 2 and the 2010 Census American Indian and Alaska Native Summary File. The 2020 Detailed DHC-A provides population counts and sex and age statistics for 300 detailed racial and ethnic groups and 1,187 American Indian and Alaska Native (AIAN) tribes and villages. The Detailed DHC-A also tabulates regional race and ethnic groups, which were not provided in prior decennial censuses. They include groups such as Caribbean, East Asian, American Indian, and Polynesian.

The Detailed DHC-A employs an adaptive design to determine the categories published for racial and ethnic groups and AIAN tribes and villages based on their population size and geography level (e.g., total population only or four, nine, or 23 age categories). The following groups will have total population counts only:

  • Detailed groups with noise infused counts of less than 500 at the nation and state levels;
  • Detailed groups with noise infused counts of 22-999 in sub-state geographies and AIAN areas;
  • Regional groups with noise infused counts of less than 5,000 at the nation and state levels;
  • Regional groups with noise infused counts of 94-4,999 in sub-state geographies.

Detailed DHC-A Minimum Noise-Infused Population Thresholds and Margins of Error (MOE) by Geography

Most comprehensive table
type produced		 Detailed Groups Regional Groups
Nation & state
(MOE=3)		 Substate* & AIANNH
(MOE=11)		 Nation & state
(MOE=50)		 Substate*
(MOE=50)
Total Count Only 0-499 22-999 0-4,999 94-4,999
Sex by age – 4 categories 500-999 1,000-4,999 5,000-19,999 5,000-19,999
Sex by age – 9 categories 1,000-6,999 5,000-19,999 20,000-149,999 20,000-149,999
Sex by age – 23 categories 7,000+ 20,000+ 150,000+ 150,000+

*Substate includes county, census tract, and place.

Users should note that the Detailed DHC-A uses a disclosure avoidance algorithm that differs from the algorithm used to protect the PL94-171 Redistricting Data, Demographic and Housing Characteristics File (DHC), and Demographic Profile. The new algorithm produces privacy-protected counts for each count and geography independently and there is no requirement that counts for lower geographies aggregate up to counts for higher geographies. Thus, the Census Bureau recommends using caution when aggregating the Detailed DHC-A data across age, sex, racial, and ethnic groups or across geographies. Additionally, counts from the Detailed DHC-A will not be consistent with counts from other 2020 Census products.

Unlike prior 2020 Census data products where exact levels of accuracy cannot be known in advance, margins of error for counts are determined in advance of running the algorithm. More information on MOEs as well as guidance on custom aggregations and comparisons to previous decennial censuses and the American Community Survey, a list of detailed race and regional groups, and a 2010 to 2020 Census race and ethnicity crosswalk can be found on the Census Bureau’s Detailed DHC-A technical documentation page.

2020 Detailed DHC-A detailed race, regional group, and Hispanic total population and age by sex tables by geography

DRU-generated extractions of total population tables for California, California counties, and the top six California places ranked by population. These extracts are organized by regional and detailed groups by major race and Hispanic origin.



Census Bureau published total population and age-by-sex tables for all available races and Hispanic origins for California, California counties, and California places accessed through data.census.gov.


Demographic Profile and DHC

The Census Bureau released Demographic Profiles and DHC tables for California, counties, places, ZCTAs, census tracts, and school districts on May 25, 2023. These profiles and tables provide basic demographic characteristics of the population including age, sex, race, households and families, type of vacancy, and tenure.

Redistricting Data (P.L. 94-171)

The U.S. Census Bureau released the 2020 Census Redistricting (Public Law 94-171) File for California on August 12, 2021. This file contains total population and population 18 years and older by race and Hispanic/Latino, total housing units, households (occupied units), vacant units, and population by type of group quarters for local geographic areas down to the census block level. In this section:

Historical 2010 and 2020 Comparisons for California, Counties, and Incorporated Cities/Towns

Note:  Historical data are provided for geographic areas with legal boundaries only.

Maps:  2010 to 2020 Population Change and Race/Ethnicity

Redistricting Data Profiles

These easy-to-use one-page, PDF profiles present the total and 18 years and older population by race (Not Hispanic/Latino) and Hispanic/Latino, housing data, and population by type of group quarters for individual geographic areas:

Data for California, Counties, Cities/Towns, and Census Designated Places (CDP)

Data for Current California State Legislative and Congressional Districts

Data for Census Tracts

Data for Block Groups and Blocks

For block level data, please refer to the Statewide Database, the official redistricting database for the state of California. They have reformatted the legacy format redistricting data file into a user-friendly version.

Additional Resources from the Census Bureau

Comments and suggestions? Please email CensusData4CA@dof.ca.gov.