Global Population Density

The world population is 6.7 billion and Earth's area is 510 million square kilometers (197 million square miles). Therefore the worldwide human population density is 6.7 billion ÷ 510 million = 13.1 per km² (34.0 per sq mi), or 44.7 per km² (115.5 per sq mi) if only the Earth's land area of 150 million km² (58 million sq mi) is taken into account. This density rises when the population grows. The total land area includes all continental (Including Antarctica) and island land area. When you take into consideration that over half of the Earth's land mass consists of areas inhospitable to human inhabitation, such as deserts and high mountains, and that population tends to cluster around seaports and fresh water sources, this number by itself does not give any meaningful measurement of human population density. However, it can draw a rough estimate that the aggregate global population density is about twice that of the above figures: approximately 230 people per sq. mile. This figure is nearly 3x that of the current U.S. arithmetic population density.

Population densities (arithmetic) for selected countries and territories (per sq mi) as of 2005.

• United States: 80
  
• Puerto Rico (US): 1280
• Bangladesh: 2,750
• Germany: 600
• India: 890
• Malta: 3,390
  
• Canada: 8
• Vatican City: 4,860
  
• United Kingdom: 640
• Bermuda (UK): 3,140
• France: 280
• Saint-Martin (Fr.): 1,610
• Denmark: 330
• Greenland (Den.): .067
• China: 360
• Macau (China): 48,450
• Hong Kong (China): 16, 380
• South Korea: 1,260
• North Korea: 480
• Monaco: 42,500
• Mongolia: 4.4
  

It is interesting to note that many of the most highly dense populations are not countries, but rather territories, dependencies, or sovereign city-states. As a matter of fact, only 10 of the top 25 most densely populated places in the world are actually classified as sovereign nation-states, with Malta being the densest and Mongolia being the least dense. In regards to land area (>100,000 km²) Bangladesh and India are the most densely populated countries in the world. Total land area seems to have a strong correlation with population density in that the larger the country's land area the lesser the population density and vice versa (only 5 of the top 50 densest countries have a land area over 100,000 km² - about the size of Iceland). Conversely, countries with over 1,000,000 km² - about the size of Egypt - have an average population density of only 107 people per sq mi; the world average is 117.

Urban Population Density

The explosion of urbanization in the last hundred years or so has created an unprecedented concentration of people in cities and metropolises. Even at the height of the Roman Empire the population densities in many of their cities was no where near today's figures. In 200 C.E. Rome had an estimated 1.2 million citizens and the entire Empire stretched nearly 3,000,000 km² and contained only about 80 million citizens. The six most populous cities in the world now comprise this same number! The overall rise in global population is a definite factor into these massive increases in urbanized populations. London, the most populated city in the world for many years, had about 6.5 million people living there in 1900. In today's ranking of urban population densities, London would not even be in the top 25. Listed below are the top ten most densely populated cities (/km²)in the world as of 2006.

1. Dhaka, Bangladesh: 45,461
2. Cairo, Egypt: 31,582
3. Delhi, India: 28,438
4. Calcutta, India: 27,462
5. Shanghai, China: 27,192
   
6. Chennai, India: 24, 547
7. Hyderabad, India: 23,403
8. Mumbai (Bombay), India: 23,088
9. Wuhan, China: 20,004
10. Ahmedabad, India: 19,185

References

Central Intelligence Agency (2008), The World Factbook: Population. Updated September 29, 2009. Retrieved from https://www.cia.gov/library/publications/the-world-factbook/fields/2119.html?countryName=World&countryCode=xx&regionCode=oc#xx

Moffett, George D. (1995), Critical Masses: The Global Population Challenge. New York, NY: Penguin Group.

Sporre, Dennis J. (2009), The Creative Impulse: An Introduction to the Arts. Upper Saddle River, NJ: Pearson Prentice Hall.

Wikipedia. (2009), List of cities proper by population. Updated April 9, 2009. Retrieved from http://en.wikipedia.org/wiki/List_of_cities_by_population