13. Greater New York, New York — 20 million
Population in 2018: 18.8 million
Note: The NY metro area includes New York City, Long Island, and the Mid and Lower Hudson Valley in New York state; Newark, Jersey City, Paterson, Elizabeth, and Edison in New Jersey; and Bridgeport, New Haven, Stamford, Waterbury, Norwalk, and Danbury in Connecticut.
11. Lagos State, Nigeria — 20.6 million
Population in 2015: 13.5 million
Note: Lagos State includes eight local municipalities.
10. Kinshasa, Democratic Republic of the Congo — 21.9 million
Population in 2015: 13.2 million
Note: Kinshasa includes four districts, which are further divide into 24 communes.
9. Greater Sao Paulo, Brazil — 23.8 million
Population in 2015: 21.7 million
Note: Greater Sao Paulo includes 39 smaller municipalities.
8. Greater Mexico City, Mexico — 24.1 million
Population in 2015: 21.6 million
Note: Mexico City's metro area includes 76 municipalities.
7. Greater Beijing, China — 24.3 million
Population in 2015: 19.6 million
Note: Greater Beijing includes the Beijing and Tianjin municipalities and Hebei Province.
6. Greater Mumbai, India — 24.6 million
Population in 2015: 20 million
Note: Greater Mumbai consists of nine local governing bodies and 15 smaller municipal councils.
5. Greater Cairo, Egypt — 25.6 million
Population in 2015: 20.1 million
Note: Greater Cairo includes the city of Cairo, as well as the surrounding districts of Giza and Qalyubia.
4. Greater Dhaka, Bangladesh — 28.1 million
Population in 2015: 19.6 million
Note: Greater Dhaka includes four districts and 11 smaller sub-units of districts.
2. Greater Tokyo, Japan — 36.6 million
Population in 2015: 37.5 million
Note: Greater Tokyo includes 23 smaller districts. The metro area is the only one in the top 13 that the UN predicts will see a decrease in population by 2030.