The population of Bhutan in 2003 was estimated by the United Nations at 2,257,000, which placed it as number 139 in population among the 193 nations of the world. In that year approximately 5% of the population was over 65 years of age, with another 39% of the population under 15 years of age. There were 102 males for every 100 females in the country in 2003. According to the UN, the annual population growth rate for 2000–2005 is 2.96%, with the projected population for the year 2015 at 3,043,000. The population density in 2002 was 20 per sq km (51 per sq mi).
It was estimated by the Population Reference Bureau that 7% of the population lived in urban areas in 2001. The capital city, Thimphu, had a population of 28,000 in that year. Phuntsholing had more than 10,000 people. According to the United Nations, the urban population growth rate for 2000–2005 was 6.0%.
Some 93% of the population was rural in 2001. The laboring population is not gathered into towns but lives in the countryside in the vicinity of fortresses called dzongs . A dzong , the official center of a region or district, often houses substantial numbers of Buddhist monks. Many place names incorporate the word dzong, which means "castle-monastery."