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Last edited 05 Feb 2020
The term ‘megacity’ refers to metropolitan areas with a total population of more than 10 million people. The definition of what constitutes a megacity generally refers to the population of an urban agglomeration, that is, it includes people living in the immediate suburbs outside of the established border of the city.
Megacities are a distinctly modern phenomenon, the proliferation of which has spread with the large-scale urbanisation that has occurred in many countries around the world. Whereas only 3% of the global population lived in cities in 1800, by the end of the 20th century that figure had risen to 47%. This figure is predicted to rise to more than 70% by the second half of the 21st century, a number made even more startling by the fact that the human population is expected to have increased by two billion by that point.
Historically, the growth of big cities first occurred during the industrial revolution, when large numbers of people moved to cities in order to find work - a trend broadly associated with developed nations. In contrast, contemporary megacity development is predominantly focused in areas of the world that are the least developed, such as Mumbai.
In 1950, the only megacities were New York-Newark and Tokyo. By 1995 the number had risen to 14. In 2016, there were 35, providing homes to 8% of the world’s population.
The 30 largest megacities, in ascending order, are:
- Tokyo-Yokohama, Japan – 37.9 million
- Jakarta, Indonesia – 30 million
- Delhi, India – 29.3 million
- Seoul, South Korea – 26.1 million
- Shanghai, China – 25.4 million
- Karachi, Pakistan – 24.3 million
- New York City, USA – 23.6 million
- Mexico City, Mexico – 22.2 million
- Beijing, China – 21.6 million
- Sao Paulo, Brazil – 21.2 million
- Lagos, Nigeria – 21 million
- Mumbai, India – 20.7 million
- Osaka, Japan – 20.2 million
- Manila, Philippines – 20 million
- Cairo, Egypt – 18.8 million
- Los Angeles, USA – 18.5 million
- Dhaka, Bangladesh – 18.2 million
- Moscow, Russia – 16.9 million
- Buenos Aires, Argentina – 16.5 million
- Bangkok, Thailand – 15.3 million
- Istanbul, Turkey – 14.8 million
- Kolkata, India – 14.7 million
- Rio de Janerio, Brazil – 14.4 million
- London, United Kingdom – 14 million
- Tehran, Iran – 13.7 million
- Guangzhou, China – 12.7 million
- Kinshasa, Democratic Republic of Congo – 12.5 million
- Shenzhen, China – 12.25 million
- Paris, France – 12 million
- Rhine-Ruhr, Germany – 11.3 million
 Related articles on Designing Buildings Wiki
- Built environment.
- Changing lifestyles.
- Cities as systems - BRE Solutions for urban environments.
- City Beautiful.
- Designing smart cities.
- Eco towns.
- Engineering Smart Cities.
- Garden cities.
- Global Construction Megacities 2017.
- Green belt.
- Landscape urbanism.
- Megatrends: Globalisation.
- Megatrends: Smart Building Technology.
- Metro cities - the future of urbanisation.
- Must cities grow to compete?
- Smart cities design timeframe.
- Smart cities.
- Sustainable development.
- The compact sustainable city.
- Urban design.
 External references
- National Geographic - The growth of megacities
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