As of April 1, 2017, the city has an estimated population of 737,812 and a population density of 1,900 persons per km2. The total area is 389.53 km2.
Greater Kumamoto (熊本都市圏) had a population of 1,460,000, as of the 2000 census. As of 2010, Kumamoto Metropolitan Employment Area has a GDP of US$39.8 billion. It is not considered part of the Fukuoka–Kitakyushu metropolitan area, despite their shared border. The city was designated on April 1, 2012 by government ordinance.