More than half of the world's population – 55% – lives in cities. By 2050, that figure is predicted to jump to 68%, according to the United Nations.
As the world continues to urbanize, a handful of countries will account for much of the growth. The U.N. estimates that by 2050, the population of urban areas could increase by 2.5 billion people, with nearly 90% of that urban growth occurring in Asia and Africa.
There are no standardized international criteria for determining the boundaries of a city, according to the U.N., and often multiple boundary definitions are available for any given urban area. The following data focuses on the world's 10 largest urban areas, or "urban agglomerations," based on projected 2020 statistics, the most recent figures released by the U.N's population division.
The U.N. also issues population growth forecasts, which project that Delhi will overtake Tokyo in the top spot, and that Kinshasa, Congo, will join the top 10 biggest cities in the coming years.