A free tool developed by Yosemite Consulting to help political media planners calculate geographic efficiency against census data—providing a more comprehensive view than voter file data alone.
This tool maps ZIP Code Tabulation Areas (ZCTAs) to political districts, counties, and cities using crosswalk data from the Missouri Census Data Center's Geocorr 2022 application (2020 Census).
How to use: Select a tab to look up data by ZCTA, political district, county, or city. Population allocation factors show what percentage of each ZCTA falls within the selected geography. Use the threshold filter to exclude minimal overlaps, and download results as CSV.
Note: ZCTAs are Census Bureau statistical areas that may not align exactly with USPS ZIP codes. District boundaries reflect the 119th Congress and current state legislative maps. California congressional districts use the 2026 redistricting maps per AB 604, sourced from the California Citizens Redistricting Commission.
Enter a ZCTA code above to see district information