The city of Paris (also called the Commune or Department of Paris) had a population of 2,165,423 people within its administrative city limits as of January 1, 2019. It is surrounded by the Paris unité urbaine, or urban area, the most populous urban area in the European Union. In 2018 the unité urbaine had a population of 10,816,803 in . The Paris Region, or Île-de-France, covers , and has its own regional council and president. It has a population of 12,213,447 as of January 2018, or 18.3 percent of the population of France. The metropolitan or functional area (aire d'attraction) of Paris covers and has 13,064,617 inhabitants (2018).
The population of the city of Paris reached a historic high of 2.9 million in 1921 but then declined; between 1954 and 1999 it declined at every census, falling to 2,125,246 in 1999. After that it began to climb again, reaching 2,240,621 in 2012, but falling to 2,187,526 in 2017.
The city's population loss reflected the experience of most other core cities in the developed world that have not expanded their boundaries. The principal factors in the process were a significant decline in household size, and a dramatic migration of residents to the suburbs between 1962 and 1975. Factors in the migration included deindustrialisation, high rent, the gentrification of many inner quarters, the transformation of living space into offices, and greater affluence among working families. The city's population loss was one of the most severe among international municipalities and the largest for any that had achieved more than 2,000,000 residents. Since then, an influx of younger residents and immigrants has contributed to the growth of the city.
Density
According to Eurostat, the EU statistical agency, in 2012 the Commune of Paris was the most densely populated city in the European Union, with 21,616 people per square kilometre within the city limits (the NUTS-3 statistical area), ahead of Inner London West, which had 10,374 persons per square kilometre. According to the same census, three departments bordering Paris, Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne, had population densities of over ten thousand persons per square kilometre, ranking among the ten most densely populated areas of the EU.
Paris is one of the most densely populated cities in the world. Its density, excluding the outlying woodland parks of Boulogne and Vincennes, was in the 1999 official census, which could be compared only with some Asian megapolises and the New York City borough of Manhattan. Even including the two woodland areas, its population density was in 2017, the sixth-most-densely populated commune in France after Levallois-Perret, Vincennes, Le Pré-Saint-Gervais, Saint-Mandé and Montrouge, all of which border the city proper.
The most sparsely populated quarters are the western and central office and administration-focused arrondissements. The city's population is densest in the northern and eastern arrondissements; the 11th arrondissement had a density of in 1999, and some of the same arrondissement's eastern quarters had densities close to in the same year.
Notes: Without the Bois de Boulogne and the Bois de Vincennes. References: INSEE
Paris agglomeration
The city of Paris covers an area much smaller than the urban area of which it is the core. At present, Paris's real urbanisation, defined by the pôle urbain (urban cluster) statistical area, covers , or an area about 27 times larger than the city itself. The administration of Paris's urban growth is divided between itself and its surrounding departments: Paris's closest ring of three adjoining departments, or petite couronne ("small ring") are fully saturated with urban growth, and the ring of four departments outside of these, the grande couronne departments, are only covered in their inner regions by Paris's urbanisation. These eight departments form the larger administrative Île-de-France région; most of this region is filled, and overextended in places, by the Paris aire urbaine, which, in 2017, was populated by over 12 million people.
The Paris agglomeration has shown a steady rate of growth since the end of the late 16th century French Wars of Religion, save brief setbacks during the French Revolution and World War II. With an estimated total of 12.2 million inhabitants for 2017, the annual population growth rate of the Île-de-France région lied between 0.3% and 0.9% over the past 50 years.