- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 23 Mar 2019
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 figure 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 megacities first emerged during the industrial revolution in which large numbers of the people moved to cities in order to find work, and it was broadly associated with developed nations. 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 are 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
 Find out more
 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.
- Indian construction industry.
- Landscape urbanism.
- 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
Featured articles and news
Modern slavery in the construction sector.
What to bear in mind when claiming damages in construction.
How do we achieve sustainable clean-water infrastructure for all?
What you should know when appointing an architect.
A brief history plus some new developments.
How computational fluid dynamics (CFD) helps building design.
The Hong Kong Harbour Area Treatment Scheme (HATS).
'Expressions of interest' for construction contracts.
Dame Judith Hackitt confirmed as keynote speaker – one year on from the Hackitt Report. Save £100 on tickets.
House of Lords committee calls for investment in housing, transport, education and infrastructure.
Supporting assets that are crucial to achieving business goals. Free download.
We've created a custom search engine for the construction industry. Let us know what you think.