The population of Afghanistan in 2003 was estimated by the United Nations at 23,897,000, which placed it as number 46 in population among the 193 nations of the world. In that year approximately 3% of the population was over 65 years of age, with another 43% of the population under 15 years of age. There were 107 males for every 100 females in the country in 2003. According to the UN, the annual population growth rate for 2000–2005 is 3.88%, with the projected population for the year 2015 at 35,473,000. The population density in 2002 was 42 per sq km (110 per sq mi).
It was estimated by the Population Reference Bureau that 22% of the population lived in urban areas in 2001. The capital city, Kabul, had a population of 2,454,000 in that year. Other major population centers include Kandaha¯r, 339,200; Mazār-e Sharif, 239,800; and Hera¯t, 166,600. According to the United Nations, the urban population growth rate for 2000–2005 was 6.9%. These figures are unreliable, however, because many city dwellers have left their urban homes for refuge in rural areas. Approximately 20% of the population is nomadic.
Two decades of near constant warfare make Afghanistan's population—never certain in any case—even more difficult to assess. As many as three million Afghans are estimated to have died, and an additional six million sought refuge in Pakistan, Iran, and elsewhere in the world during the worst of the fighting when thousands of Soviet troops were present. The last official census was taken in 1988.