Population density

Population density (people per km²) by country, 2012.

Population density (people per km²) by country, 2006.

Population density (people per km²) map of the world in 1994 (detailed).

Population density (people per km²) map of the world in 1994.

Deserts around the world. Compare with maps above. See also this image for location of densely populated areas (cities) in various vegetation zones.

Population density (in agriculture : standing stock and standing crop) is a measurement of population per unit area or unit volume; it is a quantity of type number density. It is frequently applied to living organisms, and particularly to humans. It is a key geographic term.^[1]

Lists of population density of different countries are below. Lists of other population densities are in See also section.

Biological population densities

Population density is population divided by total land area or water volume, as appropriate.^[1]

Low densities may cause an extinction vortex and lead to further reduced fertility. This is called the Allee effect after the scientist who identified it. Examples of the causes in low population densities include:^[2]

• Increased problems with locating sexual mates
• Increased inbreeding

Human population density

Monaco in South Europe, currently holds the record for being the most densely populated nation in the world.

Mongolia is the least densely populated country in the world.

This population cartogram of the European Union uses areas and colors to represent population.

For humans, population density is the number of people per unit of area, usually quoted per square kilometer or square mile (which may include or exclude, for example, areas of water or glaciers). Commonly this may be calculated for a county, city, country, another territory, or the entire world.

The world's population is around 7 billion,^[3] and Earth's total area (including land and water) is 510 million square kilometers (197 million square miles).^[4] Therefore the worldwide human population density is around 7 billion ÷ 510 million = 13.7 per km² (35 per sq. mile). If only the Earth's land area of 150 million km² (58 million sq. miles) is taken into account, then human population density increases to 47 per km² (120 per sq. mile). This includes all continental and island land area, including Antarctica. If Antarctica is also excluded, then population density rises to over 50 people per km² (over 130 per sq. mile).^[1] However over half of the Earth's land mass consists of areas inhospitable to human habitation, such as deserts and high mountains, and population tends to cluster around seaports and fresh water sources. Thus this number by itself does not give any helpful measurement of human population density.

Several of the most densely populated territories in the world are city-states, microstates, and dependencies.^[5][6] These territories have a relatively small area and a high urbanization level, with an economically specialized city population drawing also on rural resources outside the area, illustrating the difference between high population density and overpopulation.

Cities with high population densities are, by some, considered to be overpopulated, though this will depend on factors like quality of housing and infrastructure and access to resources.^[7] Most of the most densely populated cities are in southern and eastern Asia, though Cairo and Lagos in Africa also fall into this category.^[8]

City population and especially area are, however, heavily dependent on the definition of "urban area" used: densities are almost invariably higher for the central city area than when suburban settlements and the intervening rural areas are included, as in the areas of agglomeration or metropolitan area, the latter including sometimes neighboring cities. For instance, Milwaukee has a greater population density when just the inner city is measured, and the surrounding suburbs excluded.^[9]

In comparison, based on a world population of seven billion, the world's inhabitants, as a loose crowd taking up ten square feet (one square metre) per person (Jacobs Method), would occupy a space a little larger than Delaware's land area.

Most densely populated countries/regions

By inhabited region

By political boundaries

With population above 1 million

Rank	Country/Region	Population	Area (km2)	Density (Pop. per km2)
1	Singapore	5,183,700	710	7301
2	Hong Kong	7,061,200	1,104	6396
3	Gaza Strip	1,816,379	360	5045
4	Bahrain	1,234,596	750	1646
5	Bangladesh	157,457,000	147,570	1067
6	Taiwan (R.O.C)	23,361,147	36,190	646
7	Mauritius	1,288,000	2,040	631
8	South Korea	50,219,669	99,538	505
9	Lebanon	4,966,000	10,452	475
10	Rwanda	10,718,379	26,338	407

With population above 10 million

Rank	Country/Region	Population	Area (km2)	Density (Pop. per km2)
1	Bangladesh	157,457,000	147,570	1067
2	Taiwan (R.O.C)	23,361,147	36,190	646
3	South Korea	50,219,669	99,538	505
4	Rwanda	10,718,379	26,338	407
5	Netherlands	16,760,000	41,526	404
6	India	1,263,680,000	3,185,263	397
7	Haiti	10,413,211	27,750	375
8	Belgium	11,007,020	30,528	361
9	Japan	127,290,000	377,944	337
10	Philippines	100,271,800	300,076	334

Other methods of measurement

Although arithmetic density is the most common way of measuring population density, several other methods have been developed to provide a more accurate measure of population density over a specific area.

• Arithmetic density: The total number of people / area of land (measured in square miles or square kilometers ).
• Physiological density: The total population / area of arable land.
• Agricultural density: The total rural population / area of arable land.
• Residential density: The number of people living in an urban area / area of residential land.
• Urban density: The number of people inhabiting an urban area / total area of urban land.
• Ecological optimum: The density of population that can be supported by the natural resources.

See also

• Demography
• Human geography
• Idealized population
• Optimum population
• Population bottleneck
• Population genetics
• Population health
• Population momentum
• Population pyramid
• Rural transport problem
• Small population size
• Distance sampling
• List of population concern organizations

Lists of entities by population density

• List of cities by population density
• List of city districts by population density
• List of European cities proper by population density
• List of islands by population density
• List of countries by population density
• List of U.S. states by population density

References

External links

• Selected Current and Historic City, Ward & Neighborhood Densities

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