Global Population Distribution and Population Density

Global population distribution is the pattern of where people live on Earth, and population density is the average number of people per square kilometer, found by dividing the population of an area by its land area. In brief: the world has about 8 billion people, but they are spread very unevenly: most live in South and East Asia, Europe, and along coasts and river valleys, while deserts, polar regions, high mountains and dense rainforests are sparsely populated. A country of 60 million people on 240,000 km² has a density of 60,000,000 ÷ 240,000 = 250 people per km².

Understanding where people live helps explain demand for food, water, housing and services. This guide explains how density is measured, which factors shape distribution, compares densely and sparsely populated regions, works through density calculations, outlines how the world population has grown and corrects common mistakes.

How is population density calculated?

The basic formula is population density = total population ÷ land area. It is usually given in people per km². This measure is called arithmetic density and is simple, but it is an average that hides large differences within a country.

Two other measures give more detail. Physiological density divides the population by the area of arable (farmable) land, which shows the pressure on food-producing land. Agricultural density divides the number of farmers by the arable land and shows how many farmers each unit of land supports. A country can have a low arithmetic density but a high physiological density if most of its land is desert or mountain, as in Egypt, where most people live in the Nile Valley and Delta.

Where do people live?

About nine in ten people live in the Northern Hemisphere, and more than half of all people live in urban areas. Four regions hold large concentrations: East Asia (especially eastern China, Japan and Korea), South Asia (the Indian subcontinent, with fertile plains such as the Ganges), Europe and parts of eastern North America. China and India each have more than 1.4 billion people, so together they account for around a third of humanity.

Some countries have extreme densities. Singapore and Monaco are city-states with thousands of people per km², and Bangladesh has around 1,000 per km² across a large country. At the other end, Mongolia and Namibia have only a few people per km², and Greenland and Antarctica have almost none. Within countries, cities and coastal zones are far more crowded than the interior.

Which factors affect population distribution?

People tend to settle where the environment supports life and where jobs and services exist.

Physical factors

• Relief: flat, low land is easier to build on and farm than steep mountains.
• Climate: moderate temperatures and reliable rainfall attract people; extreme cold, heat or drought discourage them.
• Water supply: rivers, lakes and groundwater are essential for drinking and farming.
• Soils and resources: fertile soils, minerals and energy attract settlement.
• Natural hazards: fertile volcanic slopes and floodplains are still settled despite risks.

Human factors

• Economic opportunities: jobs in industry and services pull people to cities.
• Transport and infrastructure: ports, roads and railways encourage growth.
• History and politics: long settlement, government policy, conflict and colonization shape the pattern.
• Technology: irrigation, air conditioning and heating allow people to live in harsh places.

Dense and sparse regions compared

Worked example: density calculations

1. Arithmetic density: a country has 50 million people and a land area of 200,000 km². The density is 50,000,000 ÷ 200,000 = 250 people per km².
2. Physiological density: if only 40,000 km² of that land is arable, the physiological density is 50,000,000 ÷ 40,000 = 1,250 people per km² of arable land, five times the arithmetic density.
3. Agricultural density: if 5 million of those people are farmers, the agricultural density is 5,000,000 ÷ 40,000 = 125 farmers per km² of arable land.
4. Comparing regions: region A has 3,000,000 people on 1,500 km² (2,000 per km²) and region B has 600,000 on 120,000 km² (5 per km²). Region A is 2,000 ÷ 5 = 400 times as dense.
5. Land per person: in region A, 1 km² = 1,000,000 m², so each person has on average 1,000,000 ÷ 2,000 = 500 m². In region B, each has 1,000,000 ÷ 5 = 200,000 m².

How has world population grown?

For most of history, the number of people grew slowly. According to United Nations estimates, the world population reached 1 billion around 1804 and then grew faster as medicine, sanitation and farming improved. The time needed to add each further billion became much shorter.

Growth rates have slowed in recent decades, and most projections expect the total to peak later this century, though the exact date and level are uncertain.

Which mistakes are common?

Mistake 1: Treating the national average as the local reality

A country with moderate density can still have extremely crowded cities and empty regions.

Mistake 2: Confusing density with total population

Canada has tens of millions of people, far more than a small city-state such as Singapore, yet its density is very low because its area is huge. Total population and density answer different questions.

Mistake 3: Believing that harsh places are always empty

Technology, trade and resources can support large populations in deserts and cold regions, as in the Gulf states.

Mistake 4: Mixing up arithmetic and physiological density

Arithmetic density uses all land. Physiological density uses only arable land and is a better indicator of pressure on food production.