Population density is a measurement of the number of individuals living per unit of land area, typically expressed as people per square kilometer or square mile. It quantifies how crowded or sparsely populated a place is by dividing the total population by the land area, excluding bodies of water like lakes or rivers
. The formula for population density is:
Population Density=Number of individualsLand area\text{Population Density}=\frac{\text{Number of individuals}}{\text{Land area}}Population Density=Land areaNumber of individuals
where the land area is usually measured in square kilometers (km²) or square miles (mi²)
. Population density is widely used in geography, urban planning, resource allocation, and environmental studies. It helps governments and researchers understand population distribution, plan infrastructure, allocate resources, and analyze social and environmental impacts such as urbanization and disease spread
. For example, the global average human population density is about 16 people per square kilometer when considering the Earth's total surface, but about 53 people per square kilometer when considering only land area
. Population density varies greatly between regions, with densely populated cities like New York City having over 10,000 persons per square kilometer, while large countries with vast uninhabitable areas, like Canada or Greenland, have very low densities
. In summary, population density is a key demographic indicator that reflects how many people live in a given area, influencing many aspects of social, economic, and environmental planning.
