City population in OECD countries

Cities continue to grow, with the strongest growth in the largest metropolitan areas.

The OECD area is highly urbanised. In 2015, the vast majority of the population across OECD countries lived in urban agglomerations. The latter are defined as densely populated cities surrounded by commuting zones and are referred to also as functional urban areas (FUAs). Overall, 69% of the total population in the 33 OECD countries lived in urban agglomerations in 2015. In 29 out of the 33 OECD countries studied, that share was higher than 50% (Figure 4.1). Only in Norway, Slovakia, Slovenia, and Switzerland, the percentage of the population living in urban agglomerations was below 50%. On the other hand, in seven countries (Australia, Chile, Iceland, Japan, Korea, Luxembourg, and Netherlands), more than three-quarters of the total population reside in urban agglomerations.

4.1. Share of people living in cities, 2015
Population in functional urban areas over total population


In the 15 years between 2000 and 2015, the relative importance of functional urban areas as population centres has continued to grow. The population living in urban agglomerations grew by more than 90 million in 2000 to a total of 855 million in 2015. While all urban agglomerations in the OECD recorded, on average, positive population growth, the largest ones grew faster, on average (Figure 4.2). Large metropolitan areas, defined as those functional urban areas with more than 1.5 million residents, experienced the fastest population growth with an approximately 13% increase, on average, over this 15-year period. Metropolitan areas with a population between 500 000 and 1.5 million grew by around 11%. Medium-sized (between 200 000 and 500 000 inhabitants) and small (below 200 000 inhabitants) urban agglomerations grew by approximately 10% and 7%, respectively.

4.2. Population growth of cities by size, 2000-15
Population growth in functional urban areas



In 33 OECD countries, 1 071 functional urban areas were identified according to the OECD EU methodology that identifies functional urban areas on the basis of densely populated cities and their commuting zones (travel to work journeys) to reflect the economic geography of the population’s daily commuting patterns (see Annex A for details).

The growth patterns of functional urban areas differed significantly across continents, also reflecting national population trends. In the Americas, all types of urban agglomerations recorded high average population growth of 18-21%, with medium-sized ones growing the most. In contrast, population growth in European urban agglomerations was more modest, falling below 10% in all four categories. Larger metropolitan areas grew considerably more (9%) than medium-sized functional urban areas (5%) and small urban areas (3%). Functional urban areas in Asia and Oceania show an even more concentrated growth trajectory, with stronger growth in the largest and smallest agglomerations. While larger metropolitan areas and small urban areas grew by more than 10%, the population of metropolitan areas and medium-sized urban agglomerations remained constant.

As a result of sustained population growth in large metropolitan areas in the OECD area, there are now 102 functional urban areas with a population of at least 1.5 million, which is an increase of 11 functional urban areas relative to 2000. All of the eight most populated metropolitan areas have more than 10 million inhabitants and the three largest ones in 2015 were Tokyo, Seoul, and Mexico City with more than 35, 32, and 20 million inhabitants, respectively.


OECD (2018), “Metropolitan areas”, OECD Regional Statistics (database),

Reference years and territorial level

For lack of comparable data on commuting, functional urban areas have not been identified in Israel, New Zealand and Turkey.

Further information

OECD (2012), Redefining “Urban”: A New Way to Measure Metropolitan Areas, OECD Publishing, Paris,

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