About the Data

This tool is designed to provide visualizations of election data in Los Angeles County at the precinct level. It provides a choropleth color ramp indicating the percentage of votes cast in each precinct, along with summary data for both a county and the individual precinct. These data include:

Total Registered Voters
Total Votes Cast
Percent of Total Registered Voters Casting Ballots
Percent of All Ballots Cast by Mail
Percent of All Ballots Cast by Drop Box
Percent of All Ballots Cast In-Person
Percent of All Ballots Dropped Off at Voting Locations
Conditional Voter Registration

Additionally, a layer with information on Vote Centers or Polling Places for the 2022 Primary Election is available to toggle on or off. This visualizes the locations of Advanced and Election Day Polling Places. Data was acquired from county elections offices. On the main map, Vote Center or Polling Place icons display a hover tooltip providing information on:

Vote Center/Polling Place Type
Vote Center/Polling Place Name
Number of In-Person Votes Cast
Vote Center/Polling Place Location
Number of E-Poll Books Available
Number of Ballot Marking Devices Available

Data

For more information on the data source and calculation of these variables see below.

Percent of County Voting Age Citizens: The number of citizens in this tract who are voting age, divided by the county's total number of voting age citizens.

Data sources: American Community Survey 5-Year Estimate (2015-2019).
Calculation: The percent of the population in the tract that is eligible to vote (voting age citizen) out of the total county citizen population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Percent of County Workers: The percent of all in-county workers who work in the tracts. Query only records for people who work and live in the same county. Summarize the total number of in-county workers per block, and divide by the total number of in-county workers in the county.

Data sources: Census LEHD Origin-Destination Employment Statistics (LODES) 2019, workplace area characteristics.
Calculation: The percent of the population in the tract that work in the county out of the total number of workers that work in that county.
Scale: Census Tract

May 2022 Percent of Eligible Voters Not Registered: The percentage of voting age citizens who are not registered to vote.

Data sources: Los Angeles County RR/CC voter registration data (May 2022); American Community Survey 5-Year Estimate (2015-2019).
Calculation: Convert voter registration data to the tract level. Subtract the number of registered voters from the citizen voting age population (CVAP). Divide by the total CVAP estimate in the tract. Where the incarcerated population is over 25% of the CVAP, use the 2010 Census estimate for non-institutionalized populations instead of CVAP.
Scale: Census Tract
Limitations: Imperfect conversion of precinct to tract level.

Percent of Population with Vehicle Access: The percentage of the population with access to a vehicle.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B25044.
Calculation: The percent of households with access to at least one vehicle available.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Percent of Population in Poverty: The percentage of the population with income below the poverty level.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B17001.
Calculation: The percent of residents living below poverty in a census tract
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Population Density: The total population density per square kilometer.

Data sources: Census 2020.
Calculation: Divide the total block population by the area of the block (square kilometers).
Scale: Census Trac.
Limitations: Data shows where people live, not where they work.

2020 Percent of County In-Person Voters: The number of voters who voted at a voting location in a census tract divided by the total number of voters who voted at a voting location in the county in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert from precinct to census block level, calculate the percent of voters in a block who voted at a voting location out of the county total. Divide the number of people who voted at a voting location in the 2020 General Election in the block by the total number of people who voted at a voting location in the 2020 General Election in the county.
Scale: Census Tract
Limitations: Imperfect conversion from precinct to block level.

2020 Vote by Mail Rate (Total): The percentage of voters who voted by mail out of total voters in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert from precinct to block level, calculate as percent of total vote. Calculate the VBM rate for the total vote by dividing the number of voters who voted by mail by the total number of voters who voted.
Scale: Census Tract
Limitations: Imperfect conversion from precinct to tract level.

2020 Vote by Mail Rate (Asian-American): The percentage of Asian-American voters who voted by mail out of total Asian-American voters in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert from precinct to block level, calculate as percent of total vote. Calculate the VBM rate for the Asian-American vote by dividing the number of Asian-American voters who voted by mail by the total number of Asian-American voters who voted.
Scale: Census Tract
Limitations: Imperfect conversion from precinct to block level.

2020 Vote by Mail Rate (Latino): The percentage of Latino voters who voted by mail out of total Latino voters in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert from precinct to block level, calculate as percent of total vote. Calculate the VBM rate for the Latino vote by dividing the number of Latino voters who voted by mail by the total number of Latino voters who voted.
Scale: Census Tract
Limitations: Imperfect conversion from precinct to block level.

2020 Vote by Mail Rate (Youth): The percentage of voters between the age of 18 and 24 years old who voted by mail out of total youth voters in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert from precinct to block level, calculate as percent of total vote. Calculate the VBM rate for the youth vote by dividing the number of youth voters who voted by mail by the total number of youth voters who voted.
Scale: Census Tract
Limitations: Imperfect conversion from precinct to block level.

2020 Registered Voter Turnout Rate (Total): The percentage of total registered voters who voted in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert voting data from precinct to block level. Calculate the turnout rate for the total vote by dividing the total number of voters who voted by the total number of registered voters.
Scale: Census Tract.
Limitations: Imperfect conversion from precinct to block level.

2020 Registered Voter Turnout Rate (Asian-American): The percentage of Asian-American registered voters who voted in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert voting data from precinct to block level. Calculate the turnout rate for the Asian-American vote by dividing the number of Asian-American voters who voted by the total number of Asian-American registered voters.
Scale: Census Tract.
Limitations: Imperfect conversion from precinct to block level.

2020 Registered Voter Turnout Rate (Latino): The percentage of Latino registered voters who voted in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert voting data from precinct to block level. Calculate the turnout rate for the Latino vote by dividing the number of Latino voters who voted by the total number of Latino registered voters.
Scale: Census Tract.
Limitations: Imperfect conversion from precinct to block level.

2020 Registered Voter Turnout Rate (Youth): The percentage of registered voters between the age of 18 and 24 years who voted in the 2020 General Election.

Data sources: UCB Statewide Database Registration and Voter Data (2020 General Election).
Calculation: Convert voting data from precinct to block level. Calculate the turnout rate for the youth vote by dividing the number of youth voters who voted by the total number of youth registered voters.
Scale: Census Tract.
Limitations: Imperfect conversion from precinct to block level.

Black Percent of Population: The percentage of the population that is Black alone, not Hispanic or Latino.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03002.
Calculation: The percent of residents that are Black alone, not Hispanic or Latino in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Asian-American Percent of Population: The percentage of the population that is Asian-American alone, not Hispanic or Latino.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03002.
Calculation: The percent of residents that are Asian-American alone, not Hispanic or Latino in a tract out of the total tract population. The categories for Asian-American alone and Native Hawaiian and Other Pacific Islander alone were summed in order to get a total Asian-American population total.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Asian Indian Percent of Population: The percentage of the population that is Asian Indian.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B02015.
Calculation: The percent of residents that are Asian Indian in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Chinese Percent of Population: The percentage of the population that is Chinese.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B02015.
Calculation: The percent of residents that are Chinese in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Filipino Percent of Population: The percentage of the population that is Filipino.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B02015.
Calculation: The percent of residents that are Filipino in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Japanese Percent of Population: The percentage of the population that is Japanese.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B02015.
Calculation: The percent of residents that are Japanese in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Korean Percent of Population: The percentage of the population that is Korean.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B02015.
Calculation: The percent of residents that are Korean in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Vietnamese Percent of Population: The percentage of the population that is Vietnamese.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B02015.
Calculation: The percent of residents that are Vietnamese in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Latino Percent of Population: The percentage of the population that is Hispanic or Latino.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03002.
Calculation: The percent of residents that are Hispanic or Latino in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Mexican Percent of Population: The percentage of the population that is Mexican.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03001.
Calculation: The percent of residents that are Mexican in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Puerto Rican Percent of Population: The percentage of the population that is Puerto Rican.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03001.
Calculation: The percent of residents that are Puerto Rican in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Cuban Percent of Population: The percentage of the population that is Cuban.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03001.
Calculation: The percent of residents that are Cuban in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Dominican Percent of Population: The percentage of the population that is Dominican.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03001.
Calculation: The percent of residents that are Cuban in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

South American Percent of Population: The percentage of the population that is South American.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03001.
Calculation: The percent of residents that are South American in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Central American Percent of Population: The percentage of the population that is Central American.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03001.
Calculation: The percent of residents that are Central American in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Native American Percent of Population: The percentage of the population that is Native American.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03002.
Calculation: The percent of residents that are Native American in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

White Percent of Population: The percentage of the population that is White alone, not Hispanic or Latino.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B03002.
Calculation: The percent of residents that are White alone, not Hispanic or Latino in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Youth Percent of Population: The percentage of the population between the age of 18 and 24 years old.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B01001.
Calculation: The percent of residents between the ages of 18 to 24 years in a tract out of the total tract population.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Disabilities Percent of Population: The percentage of the population that is disabled.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B23024.
Calculation: The percent of residents with disabilities in a census tract out of the total population in the census tract.
Scale: Census Tract
Limitations: Data shows disabled population, not voters. 2015-2019 ACS data is based on 2010 census tract boundaries, while the web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Limited English Proficient Percent of Population: The percentage of the population that has limited English proficiency.

Data sources: American Community Survey 5-Year Estimate (2015-2019), Table B16001.
Calculation: The percent of the population with limited English proficiency in a census tract. Limited English proficiency is defined as people who speak English “less than very well”.
Scale: Census Tract
Limitations: 2015-2019 ACS data is based on 2010 census tract boundaries, while the Voter Turnout Tool web map displays 2020 census tract boundaries. In cases where 2010 census tracts were split into new tracts in 2020, some tracts may appear to have identical values. Future versions of the tool will use 2016-2020 ACS data which is based on 2020 census tract boundaries. In addition, estimates can have high margins of error for small samples.

Transit Stops: Transit points indicate the location of transit stops in the county and are sourced from regional General Transit Feeds (GTFS). Where GTFS data is missing local transit agency data is used instead.

Data sources: GTFS and local transit agencies. GTFS data is current as of when data was pulled by CID on November 19, 2021 and may not reflect the most up-to-date information.
Calculation: Frequency of service to each transit stop was normalized to a range of 1-4 that indicates low to high service.
Scale: Point
Limitations: Assessment of quality will be generally based on published timetables that are subject to change.

OpenStreetMap Points of Interest: A collection of crowdsourced buildings provided by OpenStreetMap.

Data sources: OpenStreetMap. OpenStreetMap data is current as of when data was pulled by CID on June 1, 2021 and may not reflect the most up-to-date information.
Calculation: N/A
Scale: Point
Limitations: OpenStreetMap is a crowdsourced database. While the organization does some validating of data, the extent and quality of a county’s coverage depends on the user.

Voting Locations: Locations previously used as a voting location, which may include 2020 General Election and 2020 Presidential Primary voting locations.

Data sources: Voting Information Project
Calculation: N/A
Scale: Point
Limitations: The accuracy of the prior voting locations used in the Tool is subject to the integrity of the data reported by counties to the Voting Information Project.

Reliability of Estimates

Some data published by the American Community Survey (ACS) rely on small sample sizes, meaning that the resulting estimates can have a high degree of uncertainty. The coefficient of variation (CV) was calculated for every ACS-based variable, where the CV is equal to the standard error (associated with 90% confidence interval) divided by the estimate (see ACS documentation, Appendix 1). Tract estimates with a CV over 40% were considered to have a high degree of uncertainty and are flagged visually on the web map with a gray square symbol.