With over 37 million residents, Greater Tokyo is the most populous metro area in the world today.

Urban growth is not unique to Japan. By 2030, the United Nations predicts that the world will have 43 megacities, defined as metro areas with more than 10 million people. Most of them will be in developing regions in the Middle East, Asia, and Africa.

The UN recently released its annual World Urbanization Prospects, which estimates which metro areas will have the highest populations by 2030.

On World Population Day this Wednesday, let’s take a look at the top 13:


13. Greater New York, New York — 20 million

Foto: A street in New York, New York.sourceFlickr

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.


12. Karachi, Pakistan — 20.4 million

Foto: Supporters of the political party Pakistan Tehreek-e-Insaf (PTI) take part in a rally near the mausoleum of Mohammad Ali Jinnah in Karachi, December 25, 2011.sourceAkhtar Soomro/REUTERS

Population in 2018: 15.4 million


11. Lagos State, Nigeria — 20.6 million

Foto: A street in Lagos, Nigeria.sourceariyo olasunkanmi/Shutterstock

Population in 2015: 13.5 million

Note: Lagos State includes eight local municipalities.


10. Kinshasa, Democratic Republic of the Congo — 21.9 million

Foto: A street in Kinshasa, Democratic Republic of the CongosourceFlickr via Antoine_Moens

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

Foto: A street in Sao Paulo, Brazil.sourceThiago Leite/Shutterstock

Population in 2015: 21.7 million

Note: Greater Sao Paulo includes 39 smaller municipalities.


8. Greater Mexico City, Mexico — 24.1 million

Foto: A street in Mexico, City, Mexico.sourceShutterstock

Population in 2015: 21.6 million

Note: Mexico City's metro area includes 76 municipalities.


7. Greater Beijing, China — 24.3 million

Foto: A street in Beijing, China.sourceThomas Peter/Reuters

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

Foto: A street in Mumbai, India.sourcePhoto by Harry Piqué on Unsplash

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

Foto: An aerial view of Cairo, Egypt.sourcePrin Adulyatham/Shutterstock

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

Foto: A farmer's market in Dhaka, Bangladesh.sourceMohammad Ponir Hossain/Reuters

Population in 2015: 19.6 million

Note: Greater Dhaka includes four districts and 11 smaller sub-units of districts.


3. Shanghai, China — 32.9 million

Foto: A street in Shanghai, China.sourceAndrew Milligan Sumo/Flickr

Population in 2015: 25.6 million


2. Greater Tokyo, Japan — 36.6 million

Foto: A street in Tokyo, Japan.sourceKoichi Kamoshida/Getty

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.


1. Greater Delhi, India — 39 million

Foto: Indian Muslim families gather in the compound of Jama Masjid to break their day-long fast in New Delhi, India, Wednesday, June 14, 2017.sourceAP Photo/Altaf Qadri

Population in 2015: 28.5 million

Note: Greater Delhi includes satellite cities including Faridabad, Gurgaon, Bahadurgarh, Noida, and Ghaziabad.