The population of Mauritania in 2003 was estimated by the United Nations at 2,893,000, which placed it as number 133 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 44% of the population under 15 years of age. There were 98 males for every 100 females in the country in 2003. According to the UN, the annual population growth rate for 2000–2005 is 2.98%, with the projected population for the year 2015 at 3,988,000. The population density in 2002 was 3 per sq km (7 per sq mi). More than 90% of the population lives in the southern quarter of the country, including the Senegal River Valley.
It was estimated by the Population Reference Bureau that 58% of the population lived in urban areas in 2001. The capital city, Nouakchott, had a population of 881,000 in that year. According to the United Nations, the urban population growth rate for 2000–2005 was 4.3%.