Population Density Calculator
Work out population density from a head count and an area in any common unit, and see the equivalent density per square kilometre and per square mile.
How it works
Population density = Number of individuals ÷ Area · Convert the area to km² or mi² to compare across regions
Population density is simply how many individuals occupy a unit of area — the crude (arithmetic) density. It lets you compare crowding between habitats or countries regardless of their total size. Because area is quoted in many units, the calculator standardises everything to square kilometres and square miles so figures line up. Real ecological density often differs from this because organisms cluster into suitable patches rather than spreading evenly.
Worked example
A survey counts 5,000 individuals across 25 km². Density = 5,000 ÷ 25 = 200 per km², which is about 200 × 2.59 = 518 per square mile. Each individual has on average 25 ÷ 5,000 = 0.005 km² of space.
Sources: Population density — Wikipedia
Frequently asked questions
What is the difference between crude and ecological density?
Crude density divides the whole population by the whole area. Ecological (specific) density divides only by the habitable area an organism actually uses, so it is usually higher because unsuitable ground is excluded.
How do I convert people per km² to per square mile?
Multiply the per-km² figure by 2.59, since one square mile equals 2.59 square kilometres. The calculator shows both automatically.
Why does area have to be greater than zero?
Density divides by area, so a zero or negative area has no meaning and would make the result undefined. Enter a positive measured area.
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This calculator is for educational purposes. Double-check important results before acting on them.