All 11,686 urban centres on Earth, measured the same way from satellite data every five years from 1975, with projections to 2030. Each tower is one urban centre and its height follows population. Press play to watch the urban world triple. Drag a globe to turn it; hover a tower to read it.
Data: European Commission, Joint Research Centre, GHS Urban Centre Database R2024A, multitemporal urban centres (GHSL), CC BY 4.0. Values for 1975–2020 are modelled from Landsat and Sentinel imagery and census data; 2025 is a nowcast and 2030 a projection.
An urban centre is defined the same way everywhere: a contiguous cluster of 1 km grid cells with at least 1,500 people per km² and at least 50,000 people in total. This is the UN-endorsed Degree of Urbanisation method. It makes cities comparable across countries, but the units are not municipalities.
Because the method follows continuous density, not city limits, some centres are far larger than the city they are named after. "Guangzhou" stands for the continuous dense settlement of much of the Pearl River Delta; several Nile Valley and Ganges Plain centres are dense rural ribbons. Low-density suburbs fall outside the centres, which is why US totals look small.
Between five-year epochs the towers grow on a log scale. A centre appears in the year it first meets the definition; centres that later merge with a neighbour fade out.