Megacity

A megacity is an urban area with more than 10 million residents. Megacities have become more numerous as urban populations have grown: there were 15 in 2000 and 33 in 2018. Tokyo had about 37.3 million residents in 2018.

Mumbai is a megacity on India’s western coast. Its population has grown as people have moved into the city and as births have exceeded deaths. Economic growth connects these processes: expanding businesses attract workers, and many young arrivals later establish families.

A megacity is an urban area with at least 10 million inhabitants. This describes its population size, not its land area or political importance. Population figures can cover the wider urban area rather than just the central administrative city, so comparisons need consistent boundaries.

A megacity has more than 10 million inhabitants. The population normally refers to the wider urban agglomeration—the continuous urban settlement—rather than just a small administrative city centre. As neighbouring settlements expand and join, they can form a conurbation.