Population density is calculated as population divided by total land area.

European city-state of Monaco is the most densely populated country with a population density of 26,337 people per sq. km (68,212/sq mile) and its population only numbers in thousands. Chinese territory of Macau has the world's 2nd highest population density at 21,717/km². Only these two have over 10,000 population per square kilometer. Population density of 3rd ranked Singapore is the highest among countries/territories having population over one million. Hong Kong and Gibraltar complete the list of top five most densely populated countries/territories. Among top 10, six are located in Asia and four are located in Europe.

All top 9 countries/territories by population density have population below 10 million. Of the 91 larger countries having population of over 10 million, Bangladesh (1,265) has greatest density followed by Taiwan (673), Republic of Korea (527), Rwanda (525) and Netherlands (508). In the list of 235, 12 have more than 1000 human per square kilometer.

Greenland is the least densely populated territory in the world with 0.14 people per sq. km. With 2.1 people per square km, Mongolia is the least densely populated country followed by Namibia and Australia. Five least dense countries over population of 10 million are : Australia (3.32) Canada (4.15), Kazakhstan (6.96), Russian Federation (8.91) and Bolivia (Plurinational State of) (10.78).

Out of countries having at least 10 mn people, Top ranker Bangladesh is 38 times as dense as the lowest ranker Australia.