Population density
How many people live in each square mile of land here.
The number of residents per square mile of land.
The numerator is the total resident population the Census Bureau publishes for the place, counted under its residence rules: a person is counted where they live and sleep most of the time, which is not always where they are on the day of the survey (ACS Subject Definitions).
The denominator is land area, taken from the Census Bureau's 2025 Gazetteer files, which publish the measured land and water area of every tract, county and ZIP Code Tabulation Area (Gazetteer Files). Land area only: the water part of a place's footprint is excluded, so a waterfront neighbourhood is not made to look empty by the bay beside it. For metropolitan areas, land area is the sum of the land in the counties that make up the area.
Metrics in this family#
Population density
levelResidents per square mile of land, from the most recent 5-year population estimate over the current published land area.
Considerations#
Density is the most direct measure of what a place physically feels like, and it separates two places that population alone reports as identical: ten thousand people in half a square mile and ten thousand people spread over forty are not the same neighbourhood.
It is a ratio of a survey estimate to an administrative measurement, and the two are published on different schedules. The population moves every vintage; the land area moves only when boundaries are redrawn or the Bureau re-measures. A change in density is therefore almost always a change in population.
Land area is the whole land footprint of the place, including parks, airports, industrial land and anything else nobody lives on. A tract containing a large airfield or reservoir reads as far less dense than the part of it people actually live in.
Density spans several orders of magnitude between rural tracts and dense urban ones, which is worth remembering when comparing two places far apart on it: the gap between 50 and 500 residents per square mile is a bigger difference in kind than the gap between 20,000 and 20,500.
The measure is published as a level only; no trend is computed for it.
Census tract boundaries were redrawn for the 2020 census, and both the population estimates and the land areas used here are on current boundaries — see geography.
References#
- 1ACS Subject Definitionshttps://www2.census.gov/programs-surveys/acs/tech_docs/subject_definitions/2024_ACSSubjectDefinitions.pdf
- 2Census Bureau Gazetteer Fileshttps://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.html