List of agglomerations by population

This is a list of agglomerations (ie built up areas when available) with population over one million people as of july 2011 based on the census data according to citypopulation.de. The delimitation was made on Google Earth for built up areas by Franck MICHEL adjusted on Local Government Areas available on citypopulation.de and mainly on counties or districts for USA, China and India (updated on july 2011).

These statistical are based on the French concept : "unité urbaine" (literally: "urban unit") which is a statistical area defined by INSEE, the French national statistics office, for the measurement of contiguously built-up areas. According to the INSEE definition [1], an "unité urbaine" is a commune alone or a grouping of communes which: a) form a single unbroken spread of urban development, with no distance between habitations greater than 200 m and b) have altogether a population greater than 2,000 inhabitants. Communes not belonging to an unité urbaine are considered rural.

The French unité urbaine is a statistical area in accordance with United Nations recommendations for the measurement of contiguously built-up areas. Other comparable units in other countries are the United States "Urbanized Area" and the "urban area" definition shared by the United Kingdom and Canada.

Approximately one quarter of all population lives in these metropolises. The following countries have the most of such cities, which indicates their status (two main blocs - first world or developed countries, and BRIC that emerged as a new second world are present):