Population Density
The number of people per unit of land area (typically per square mile or square kilometer), used to classify ZIP codes as urban, suburban, or rural.
Population density is one of the most fundamental demographic metrics associated with ZIP codes. It is calculated by dividing the total population of a geographic area by its land area (excluding water bodies). In the United States, density is typically reported in persons per square mile.
ZIP code population density varies enormously: Manhattan's 10001 has over 70,000 people per square mile, while rural ZIPs in Nevada or Montana may have fewer than 1 person per square mile. The Census Bureau's ZCTA data provides population and land area figures that allow density calculation.
Population density drives countless business decisions: retail site selection, advertising media planning, logistics routing, healthcare access analysis, and infrastructure planning. Insurance companies, real estate firms, and political campaigns all use ZIP-level density data.