POPULATION DENSITY: CONCEPT, HOW IT IS CALCULATED AND EXAMPLES - GEOGRAPHY - 2025

The population density is the number of inhabitants per unit land area. It is often expressed as the number of people per square kilometer or square miles of the chosen territory, which can be as large as a continent, a country, a city or a district.

It also assumes that the population is distributed homogeneously throughout the territory, even though it has inhospitable areas such as very arid deserts, steep mountains or dense forests.

Figure 1. Population density is an important indicator when planning the use of resources. Source: Pixabay.

Other names for population density with the same meaning are population density and relative population, since it is expressed by a quotient that compares the number of people with the size of the territory:

Population density = D _P = Number of inhabitants / Area in kilometers or square miles

Population density concept

Although we know that people are not evenly distributed, population density is a very important population indicator.

People demand a minimum of conditions to survive. For this reason, from the first societies, humanity sought to establish itself in places that offered a moderate climate, sufficient water, fertile soils, and appropriate communication routes.

When it comes to planning resource use, it is not enough to know the absolute number of people. Effective distribution requires knowing where more people are clustered and where there are fewer, in order to meet requirements such as food, electricity, transportation, and communications, to name just a few.

According to what has been said, a small territory inhabited by few people, can have a high population density, it is no longer about absolute quantities. And a country with a large population is not necessarily densely populated if it has a large territory, as we will see later.

How is population density calculated?

Population density is the ratio between the number of individuals and the area of ​​the territorial surface. Therefore, it is necessary to have the numerical values ​​of the population and the area to which it belongs.

Censuses and measurement of areas

One way of knowing the number of individuals is by counting everyone through a census. The word census derives from the Latin census and censare, a count of people that was done in Ancient Rome to know how many men were available for military service and also for tax purposes. Censuses were of course carried out in other places, like ancient China, for example.

The governments of each country are responsible for carrying out population censuses, interviewing each and every one of the inhabitants. This is not always easy in very remote areas and in any case it is a large-scale task that requires a great deal of time and resources.

Another simpler way to approach the problem of people counting is through sampling techniques.

With this, the population is estimated from a sample. The results can be quite accurate and this method is used mainly for smaller studies, where smaller geographic areas are considered or when census data are not up-to-date.

And to find the areas of the corresponding territory, maps, aerial photos, satellite images and cartographic techniques are used. Artificial satellites like Landsat and others provide very good quality data. In general, the delimitation of a territory can be complicated, in view of the large number of factors that must be evaluated.

Examples of population density in the world

According to the figures that the World Bank handles, there are 149 million square kilometers of land, of which only 10% contains 95% of the planet's population. The rest is uninhabited for various reasons, one of the main ones being extreme weather.

Figure 2. Map of population density around the world. Desert sites, with dense or very cold forests, have the lowest densities. Source: Wikimedia Commons. Ms Sarah Welch.

The places with the highest population density also have other qualities apart from the climatic conditions, such as ease of communication, the quality of the soils for cultivation, availability of resources, especially water, and political and social stability, to name a few..

Historically the lowlands, those close to rivers, fresh water sources and coastal areas have been preferred by humanity to establish their settlements. It is enough to remember that civilizations such as the Egyptian and Mesopotamian flourished thanks to rivers such as the Nile, the Euphrates and the Tigris.

Below is the calculation of the population density of various countries with different territorial extensions and climatic conditions:

England

According to data taken from the network, the total area of ​​England is 130,395 ^km² and a population of 53,012,456 inhabitants. Its population density is:

D _P = 53,012,456 inhabitants / 130,395 ^km² = 407 inhabitants / ^km²

England's population density is one of the highest in Europe, but not the highest.

Mexico

With an area of ​​1,964,375 ^km² and a diversity of landscapes, Mexico is home to 123,982,528 people. The Mexican population density is:

D _P = 123,982,528 inhabitants / 1,964,375 ^km² = 63 inhabitants / ^km²

Even having more than twice the population of England, the relative density is much lower, due to the size of the country.

Spain

Spain has 505,944 ^km² of extension and 46,934,600 inhabitants. The calculation of its population density is:

D _P = 46,934,600 inhabitants / 505,944 km ² = 93 inhabitants / km ²

A good percentage of Spanish territory is not inhabited, so the global density is low compared to other European countries. But the inhabited areas are highly populated, especially its main cities.

Canada

This is the second country in the world in territorial extension: 9,093,469 ^km² and a population of 37,590,000 inhabitants. Your D _P is:

D _P = 37,590,000 inhabitants / 9,093,469 ^km² = 4 inhabitants / ^km²

Compared with previous densities, that of Canada is much lower, however, it must be considered that much of it has an inhospitable climate and not very conducive to agriculture. That is why most of the population is distributed towards the south and along the coastal areas, where the climate is a little less severe.

Countries with higher population density

According to data provided by government organizations, currently the countries and territorial agencies with the highest population density, in increasing order, are shown in the following table:

Table 1. Countries and territorial dependencies with the highest population density.

Country or dependency	Number of inhabitants	Extension in km 2	Population density in inhabitants / km 2
Monaco	38,300	2.02	18,960
Singapore	5,638,700	722.5	18,960
Hong Kong (China)	7,482,500	1,106	6,765
Bahrain	1,543,300	778	1,984
Maldives	378,114	298	1,269
malt	493,559	315	1,567
Bangladesh	167,764,312	143,998	1,165
Palestine	4,976,684	6,020	827
Barbados	287,025	430	668
Lebanon	6,855,713	10,452	656
Taiwan	23,596,266	36,197	652
Mauricio	1,265,577	2,040	620
San Marino	34,641	61	568

Results for population density are rounded to the nearest integer. Looking closely at the data, it is noted that for the most part, the most densely populated countries have small territories, except for Bangladesh, which exceeds 100,000 km ^² in area.

Figure 3. View of the principality of Monaco in southern Europe, the most densely populated country in the world. Source: Wikimedia Commons. Alexander Migl

Countries with lower population density

At the other extreme are the countries with a lower density, which unlike the previous ones, have a notable territorial extension, but which due to their geographical characteristics is less favorable for human settlements.

The following table shows the countries with the lowest population density, in increasing order of density:

Table 2. Countries and territorial dependencies with the lowest population density.

Country or dependency	Number of inhabitants	Extension in km 2	Population density in inhabitants / km 2
Greenland	56,770	410,448	0.14
Falkland Islands	3,480	12,170	0.30
Mongolia	3,112,827	1,553,553	2.00
Occidental Sahara	549,000	266,000	2.06
Namibia	2,030,692	824,292	2.46
Libya	5,670,688	1,759,540	3.22
Australia	25,043,027	7,741,220	3.24
Iceland	357,050	103,000	3.47
French Guiana	282,731	83,534	3.40
Surinam	558,368	163,820	3.41
Guyana	801,193	214,969	3.70
Botswana	2,250,260	581,730	3.87

Note: Although the number of inhabitants is a whole number, the population density can give a decimal number. In Table 2 the results are rounded to two decimal places.

Countries such as Greenland and Iceland, located in the Arctic have too cold a climate, Australia, Namibia and Western Sahara, for example, have vast deserts, while the territory of Guyana, French Guiana and Suriname, located in South America, are covered by dense rain forests.

Cities with higher population density

The largest number of people congregate in large cities, because they offer many more job opportunities, as they have highly diversified activities.

Cities with the highest population density are not necessarily those with the most inhabitants. Currently, the large Chinese cities are those with the highest number of inhabitants, however in Table 3 of the most densely populated cities there are no Chinese cities among them.

Figure 4. View of the city of Dhaka in Bangladesh, the most densely populated city in the world. A frequent problem in densely populated cities is traffic jams. Source: Wikimedia Commons. ASaber91

This is due to the large size of these cities. Chongqing, located in southwest China, is currently the largest city in the world.

Figure 5. View of Chongqing, China, the largest and most populous city in the world. Source: Wikimedia Commons. Chlich

It has no less than 30,165,500 inhabitants in an area of ​​82,403 ^km², which is much larger than the other cities on the list.

Table 3. The most densely populated cities around the world.

City	country	Number of inhabitants	Extension in km 2	Population density in inhabitants / km 2
Dhaka	Bangladesh	14,399,000	337.54	42,659
Cairo	Egypt	7,601,018	473.73	25,582
Kinshasa	Congo	11,462,000	337.54	24,195
Delhi	India	6,787,941	1,484	23,893
Tokyo	Japan	13,515,271	626.99	21,556
Mumbai	India	12,442,373	603	20,634
Bogota	Colombia	7,963,000	428.26	18,594
Ho chi min city	Vietnam	7,431,000	453.60	16,382
Riyadh	Saudi Arabia	6,694,000	410.97	16,288
Seoul	South Korea	9,806,000	605.25	16,202
Jakarta	Indonesia	10,624,000	661.50	16,060
Baghdad	Iraq	6,793,000	424.53	16,001
Dar es salaam	Tanzania	5,257,000	330.52	15,905
Chennai	India	6,727,000	426.51	15,772
Mexico City	Mexico	8,918,653	607.22	14,616
Tehran	Iran	9,033,003	751	12,028
Bangalore	India	8,443,675	709	11,909
New York	U.S	8,398,748	786.30	10,681

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