How cities are defined: one rule for every country
Countries define “urban” in very different ways, so their numbers cannot be compared directly. The UN World Urbanization Prospects 2025 use the degree of urbanisation instead: on a grid of 1 km² cells, a city is a contiguous dense area of at least 1,500 people per km² with at least 50,000 people. The same rule applies everywhere.
Why national definitions do not compare
Some countries call any settlement of a few thousand people urban, others use administrative status, and others count only large municipalities. A town classed as urban in one country might be rural in its neighbour. Adding these numbers up gives a world total that mixes very different things.
The degree of urbanisation
The method starts from a grid of 1 km² cells, each with its estimated population, and classifies every cell:
- Cities: contiguous cells with at least 1,500 people per km² that together have at least 50,000 people.
- Towns and semi-dense areas: contiguous cells with at least 300 people per km² that together have at least 5,000 people, outside cities.
- Rural areas: all other cells.
Because the rule depends only on density and size, it gives comparable numbers for every country. The urbanisation topic shows the shares of the world population in cities, towns and rural areas by this rule.
What a city on Anthrotempo is
A city page shows the dense area drawn on the grid, not the municipality. Where several cities have grown together, they form one area. That is why a city’s population can be larger or smaller than the figure in national statistics, and why some well-known names are part of a larger area.
Cities are listed when they reach 50,000 people. Years from 2026 on are UN projections. The city directory lists every city of a million people or more.
Last updated 26 October 2026