The latest United Nations studies confirm that the world population continues to increase and points the number to close to 7700 million people. Much more than 4 billion in 1974 but also much less than the 10 billion expected in 2057.
Since the industrial revolution that began in the mid-18th century, migration from the countryside to the cities has not ceased to invert the balance and bring the world population closer to large cities. This phenomenon occurs throughout the planet and if we look at the data of the 20 most populous cities in the world they host 5% of the total world population.
Increasingly, the exodus from the countryside to the city is growing, and currently of those 7700 million people, about 385 million, live in one of the 20 megacities of the planet. These are divided between 12 large cities in Asia, 4 in America, and 4 in Africa.

Below we show you the ranking of the most populated cities in the world based on 2020 data estimated by the United Nations.
1. Tokyo, Japan with 37.4 million
The Japanese capital has 37.4 million and a negative change of -0.11% compared to the previous year.
2. Delhi, India with 30.2 million
The big city in India reaches 30.2 million with an increase of + 3.03% compared to last year.
3. Shanghai, China with 27 million
Shanghai, the great Chinese city, reaches 27 million inhabitants with an increase of + 2.8%.
4. São Paulo, Brazil with 21.8 million
São Paulo is the first American city to appear in the ranking with its 21.8 million people and an increase of + 0.9%.
5. Mexico City, Mexico with 21.7 million
The second American city and the first Spanish-speaking city is Mexico City with 21.7 million and an increase of + 2.0%.
6. Dhaka, Bangladesh with 21 million
The capital of Bangladesh appears in the sixth position with 21 million souls and a + 3.6% increase over the previous year.
7. Cairo, Egypt with 20.9 million
The capital of Egypt is the first African city to appear in the ranking with 20.9 million and a rise of + 2.03%.
8. Beijing, China with 20.4 million
The capital of China appears in the eighth position with its current 20.4 million and a growth of + 2.13%.
9. Mumbai, India with 20.4 million
Mumbai is the second city in India to appear on the list with 20.4 million and a rise of + 1.12%.
10. Osaka, Japan with 19.1 million
Japan appears again represented in position number 10 with Osaka with 19.1 million people and a negative increase of -0.30%.
11. Karachi, Pakistan with 16 million
The first Pakistani city appears with its 16 million souls and an increase of + 2.24% over the previous year.
12. Chongqing, China with 15.8 million
Chongqing is the third Chinese city to appear with 15.8 million and an increase of + 3.37%.
13. Istanbul, Turkey with 15.2 million
The old Istanbul and capital of Turkey with 15.2 million people and an increase of + 1.35%
14. Buenos Aires, Argentina with 15.1 million
The Argentine capital is the third American city to appear and the second Spanish-speaking city with 15.1 million inhabitants and an increase of + 1.49%.
15. Calcutta, India with 14.8 million
Calcutta, the third city of India, amounts to 14.8 million people with an increase of + 0.64%.
16. Lagos, Nigeria with 14.3 million
The capital of Nigeria is the second African to appear with its 14.3 million and an increase of + 3.34%.
17. Kinshasa, Congo with 14.3 million
The capital of the Congo is the third capital of the African continent to come out in the ranking with its 14.3 million and growth of + 4.36%.
18. Manila, the Philippines with 13.9 million
The capital of the Philippines has 13.9 million with a + 1.64% increase.
19. Tianjin, China with 13.6 million
China again appears with Tianjin and its 13.6 million people and an increase of + 1.44%.
20. Rio de Janeiro, Brazil with 13.5 million
Rio de Janeiro is the second-largest city in Brazil with 13.5 million and an increase of + 0.63% over the previous year.