# Population density

Population density (people per km2) by country, 2015
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.

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.

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:

• 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, and Earth's total area (including land and water) is 510 million square kilometers (197 million square miles). 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). 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. 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. Most of the most densely populated cities are in Southeast Asia, though Cairo and Lagos in Africa also fall into this category.

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 sometimes including neighboring cities. For instance, Milwaukee has a greater population density when just the inner city is measured, and the surrounding suburbs excluded.

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
Region Population Area (km2) Density
(Pop. per km2)
Indo-Gangetic Plain (Punjab to Bangladesh and Assam) 1 billion 1,000,000 1000
Greater North China Plain 600 million 700,000 857
Sichuan Basin 110 million 250,000 440
Java Island 145 million 130,000 1115
Taiheiyo Belt (Japan) 85 million 60,000 1417
SE China coast (Guangdong, Hong Kong, Fujian) 140 million 100,000 1400
Nile Delta 50 million 50,000 1000
Southern India (Tamil Nadu, Pondicherry, Bengaluru, and Kerala) 120 million 170,000 706
West Indian Coast (Maharashtra and Gujarat Coast) 70 million 100,000 700
Colombian Andes (Colombia) 40 million 170,000 235
Northern Europe (Benelux, North Rhine-Westphalia) 44 million 110,000 400
NE US Coast 45 million 100,000 450
S Central England 40 million 60,000 667
Central Mexico 40 million 100,000 400
Luzon Island 50 million 105,000 476
South Korea 50 million 100,000 500
Southeastern Brazil Coast 50 million 100,000 500
##### 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
6  Taiwan (R.O.C) 23,361,147 36,190 646
7  Mauritius 1,288,000 2,040 631
8  Lebanon 5,851,000 10,452 560
9  South Korea 49,115,196 99,720 493
10  Rwanda 11,262,564 26,338 428
With population above 10 million
Rank Country/Region Population Area (km2) Density
(Pop. per km2)
2  Taiwan (R.O.C) 23,361,147 36,190 646
3  South Korea 49,115,196 99,720 493
4  Rwanda 11,262,564 26,338 428
5  Netherlands 16,919,139 41,526 407
6  India 1,263,680,000 3,185,263 397
7  Haiti 10,413,211 27,750 375
8  Belgium 11,239,755 30,528 368
9  Philippines 102,078,300 300,076 340
10  Japan 127,290,000 377,944 337

#### 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.