International urban sprawl

The number and size of major cities has grown dramatically in the last half century. In 1950 there were only 75 cities with a population of more than 1m people, according to UN data, but by 2010 there were 442 such conurbations – nearly a six-fold increase.

This rapid growth has been most noticeable in the emerging markets where Delhi, ranked as only the world’s 16th biggest city in 1950 with 1.4 m inhabitants had by 2005 grown to be the world’s second-biggest city with a population in excess of 19.5m.

Explore which other cities have been shooting up the rankings in this interactive graphic.