data japan 2023The 2025 population density in Japan is 338 people per Km2 (875 people per mi2), calculated on a total land area of 364,555 Km2 (140,755 sq. miles). Largest Cities in Japan # City NamePast Test Data ; 2025, 92, 1,481,023 ; July, 55, 698,062 ; December, 85, 782,961 ; 2022, 89, 932,518