demographics of the world include population density, ethnicity, education level, health measures, economic status, religious affiliations and other aspects of the human population of earth.
the world's overall population density is 50 people per km² (129.28 per sq. mile), excluding antarctica. nearly two-thirds of the world's population lives in asia, with more than 2.5 billion in the countries of china and india combined. the world's literacy rate has increased dramatically in the last 40 years, from 66.7% in 1979 to 86.3% today. this low rate is mostly attributable to poverty. lower literacy rates are mostly found in south asia, west asia and sub-saharan africa.
the world's largest ethnic group is han chinese, with mandarin being the world's most spoken language in terms of native speakers.
the world's population is predominantly urban and suburban, and there has been significant migration toward cities and urban centres. the urban population jumped from 29% in 1950 to 55.3% in 2018. working backwards from the united nations prediction that the world will be 51.3 percent urban by 2010, dr. ron wimberley, dr. libby morris and dr. gregory fulkerson estimated 23 may 2007 would have been the first time the urban population outnumbered the rural population in history. china and india are the most populous countries, as the birth rate has consistently dropped in developed countries and until recently remained high in developing countries. tokyo is the largest urban conglomeration in the world.
the total fertility rate of the world is estimated at 2.43 (2017, world bank) children per woman, which is above the global average for the replacement fertility rate of approximately 2.33 (as of 2003), meaning the world's population is growing. however, world population growth is unevenly distributed, with the total fertility rate going from 0.83 in singapore, to 6.49 in niger. the united nations estimated an annual population increase of 1.14% for the year of 2000.
the current world population growth is approximately 1.09%. people under 18 years of age made up over a quarter of the world population (29.3%), and people age 65 and over made up less than one-tenth (7.9%) in 2011.
the world population more than tripled during the 20th century from about 1.65 billion in 1900 to 5.97 billion in 1999. it reached the 2 billion mark in 1927, the 3 billion mark in 1960, 4 billion in 1974, and 5 billion in 1987. the overall population of the world is approximately 7.7 billion as of december 2018. currently, population growth is fastest among low wealth, least developed countries. the un projects a world population of 9.15 billion in 2050, which is a 32.69% increase from 2010 (6.89 billion).