Megacities – places with a population of 10 million or more – are emerging around the globe, and especially in developing countries. It’s more than just population where these cities dominate. They typically comprise a significant proportion of a country’s gross domestic product (GDP) and drive much of the economy.

In 1990 there were just 10 megacities, which has tripled to 33 today. By 2050, the United Nations (UN) predicts there will be 47 megacities, with two out of every three people on earth living in an urban area. Click or scroll through to find out which cities will dominate, ranked by their projected 2050 populations as predicted by the Institute for Economics and Peace.

All dollar values in US dollars.

China is expected to have eight megacities by 2050, six of which already have populations beyond the 10 million mark.

Located in the Yangtze River Delta, with relatively close proximity to Shanghai, the ancient city of Nanjing had a population of 9.5 million in 2022. With several prominent universities, along with research centres funded by foreign companies, the city has been targeting college graduates and other younger workers with subsidies to cover housing and travel costs for job interviews and relocation. Most estimates predict the city will reach a 10 million population before 2030.

By population, Nairobi is the smallest city on this list at 5.2 million people in 2022. However, the capital of Kenya is expected to double its population over the next few decades making it one of the fastest growing cities in the world. Its central location with road, rail and air connections across the African continent, have made it a hotspot for finance, commerce and international diplomacy. The city generates around 45% of national GDP, and foreign investors have poured money into Nairobi’s rapid urbanisation.

That said, new infrastructure and development have not been beneficial for all residents. It’s estimated as much as half of Nairobi still lives in informal settlements and these neighbourhoods are likely to absorb much of the forthcoming population growth.

Comparatively more modest growth is expected for Tehran, whose population is already at 9.4 million. The city saw significant increases during the Iran-Iraq War in the late 1970s and early 1980s as families left border regions, and migration into the city has continued ever since. Planners have taken a super-charged approach to developing the sprawling city to its utmost limits in an attempt to cope with the on-going influx of new residents, though others are concerned Tehran may be at its current capacity.

Chengdu is the second Chinese location forecasted to reach megacity status by 2050, and has the same current population as Nanjing at 9.4 million. Capital of the Sichuan province, it’s a major player in western China for transportation, finance and communications, and has seen rapid economic growth over the last decade. The city has actively encouraged rural-to-urban migration, bringing in workers for Chengdu’s major industries including electronics, pharmaceuticals, chemicals, foodstuffs and light textiles.

By 2050, it’s estimated nine of the world’s megacities will be in India, and currently only three of those cities are below the 10 million population threshold.

Around 7 million people currently live in Pune, though that number was recently much lower when it was considered something of a “pensioners’ paradise”. Its rapid urbanisation has brought millions more people into the city as industries moved in and workers followed. Located southeast of Mumbai, many lament the loss of Pune’s green spaces and the lack of more affordable housing, while others are arguing for better transport connections including its own airport.

Only four North American cities make the list, and three are in the US. Chicago, with its current population of 8.9 million is forecasted to increase by 21% through 2050, making it a megacity. In fact, it’s likely the city will see a population of 10 million before the decade is out. Its Midwest location makes Chicago a hub for transportation, finance, education and culture, and an easy connection to either coast. Another advantage is its diverse economy with no industry accounting for more than 13% of its GDP.

Europe makes up very few of the world’s megacities and with a population of 9.6 million, London is expected to exceed the 10 million mark much sooner than 2050. Over the last three decades, the UK’s largest city has become a hub for the global finance industry, drawing in significant foreign investment and fuelling a construction boom. Immigration has fed much of London’s growth, as the city outpaces the rest of the country. London accounts for nearly a quarter of the UK’s economy and around 13% of its population.

Like London, Sudan’s capital city has grown rapidly over the last three decades, now making up 19% of the country’s population. However, that’s where the similarities end. Migration, due to a lack of resources including water and fertile land, along with the absence of an urban plan, have resulted in a sprawling, low-built urban area that has expanded at rate once described as “almost out of control”. Informal settlements contribute to a not-insignificant portion of this growth, and Khartoum is forecasted to further grow by a whopping 80% from 6.2 million in 2022 to 11.2 million.

This rapidly growing city in the state of Gujarat has several industries drawing in migrants from around the region and from other states in India. It boasts 90% of the world’s diamond cutting and polishing business, a healthy portion of India’s textile and fibre industry, and a very low unemployment rate. Currently, 7.9 million people live in Surat, making it one of the smaller cities on this list, however, it is expected to reach 12 million people by 2050. And the city’s diamond dominance has paid off bringing the GDP from $8 billion (£6.4bn) in 2008 to $28 billion (£22bn) in 2018, according to Oxford Economics.

With a population of 12.7 million as of 2022, Moscow is already a megacity. However, it’s one of three on this list that is forecasted to experience population declines over the next few decades. As a whole, Russia has seen its population plummet since the fall of the Soviet Union, and while Moscow is its biggest city, it’s not immune to issues of lower birth rates and the brain drain associated with talented young people leaving home to work abroad. More recent demographic analysis suggests that the war with Ukraine and the economic crisis stemming from related sanctions may also have an impact on the already low birth rate.

By population Paris is already a megacity with 11.2 million people living there in 2022. While not growing at a pace as rapid as predicted for many other cities on this list, the French capital is projected to continue seeing population increases to 12.4 million in 2050. Much like London, it’s more than just population making Paris a megacity: it's the seat of the national government and represents 30% of France's GDP. 

However, this has had an impact on where people are living. Recent statistics show a shift with people leaving the city centre to live its outer suburbs where housing is less expensive.  

As of 2022, around 7.6 million people lived in Baghdad, Iraq's capital and largest city. However, it's forecasted to see a 71% increase through to 2050 — one of the highest rates of growth on this list. Iraq is already a highly urbanised country, with only 30% of its population living in rural areas. However, Baghdad has double the population of the next largest city, Mosul, and has seen an influx people moving in due to sectarian violence in other cities. 

While the impact of the US-led invasion and occupation over the last 20 years is still prominent in Baghdad, it remains a hub for trade, transportation and culture within both Iraq and the wider region.

Like Surat, Ahmedabad is located in Gujarat, north of Mumbai. Its proximity to other megacities in India has helped fuel an economic expansion over the last few decades. Not surprisingly, the city has steadily grown in population at the same time, with many worried it may be at capacity. Recently, the local government outlined a plan to develop satellite towns to help ease the city’s congestion and housing issues. In 2022, 8.5 million people lived in Ahmedabad and that’s expected to grow to 13 million by 2050.

Ho Chi Minh City only accounts for around 10% of Vietnam’s population, however it makes up nearly a quarter of its GDP. Migration from rural areas has contributed to its current population of 8.7 million, and as the country’s economic powerhouse — one that’s attracting foreign investment — that’s not likely to abate. A series of smart city and infrastructure programmes will further increase growth, reaching a projected population of 13 million by 2050. 

There are currently four megacities in South America and while these will continue to grow, no other cities on the continent are expected to reach the 10 million population mark by 2050.

Lima is home to one-third of Peru’s population and much of this is due to rural-to-urban migration starting in the years after the Second World War. The city accounts for almost half of Peru’s GDP, however there’s rampant inequality with estimates of around 20-30% of Lima’s residents reported to live in shantytown type conditions due to a shortage of housing. Currently 11.1 million people live in Lima, and another 2 million people are expected to be added to its population over the next three decades. 

With the same current population as Lima, at 11.1 million, there’s even more growth forecasted for Jakarta, and that’s despite estimates that more than a third of the city could be submerged by 2050. By far the country’s largest city, Jakarta is sinking due to ground water removal and rising seas due to climate change. It also struggles with congestion and related concerns due to its overwhelming population density. All things considered, the government has decided to build a new capital in Borneo, which will likely be completed around 2045. Even with all government operations moving away, it’s anticipated Jakarta will continue to be the country’s commercial and financial centre, keeping its megacity population through 2050.

Unlike many of the ancient and historic cities on this list, Shenzhen as a city dates back only to 1979 when it was a sleepy fishing village. It was China’s first “special economic zone” and a resounding success. The region attracted a number of big players in the manufacturing and tech industries and the population grew rapidly, reaching the 10 million megacity mark in 2010. It’s grown by another 3 million people since and is the third largest city in China by GDP.

Shenzhen is also one of the cities in China’s Pearl River Delta, a continuously urbanised area that also includes the cities of Guangzhou, Foshan and Dongguan that is home to around 60 million people.

Thailand has been celebrated as an economic success, developing into an upper middle-income country over the last 40 years, and making impressive reductions in poverty from 58% in the 1990s to less than 7% in 2020. However, those who continue to struggle financially are heavily concentrated in rural areas with Bangkok driving much of the economic growth, as is often found with megacities.

Not surprisingly, internal migration accounts for a significant portion of the capital city’s growth, especially from the less-developed northern and north-eastern regions. And with a 2022 population of 10.9 million, Bangkok is expected to grow by another third over the next few decades to 14.4 million.

A lack of planning control meant that much of Rio de Janeiro’s 20^th century growth came about in self-built neighbourhoods or “favelas”, home to nearly a quarter of the city’s population, and contributing to heightened inequality.

Over the next few decades relatively less population growth is expected in Brazil’s second largest city, already home to 13.7 million people in 2022. No longer the economic powerhouse it once was, the city’s contribution to national GDP has been dropping from 12.5% at the start of the century to around 10% more recently. The projected 2050 population of 14.6 million will only be a 7% increase.

Following nearly three decades of civil war, Angola experienced dramatic economic growth in the early 21^st century thanks to its oil reserves and diamond mines. And alongside this prosperity, the population of capital city Luanda more than trebled to 9 million in 2022.

However, the oil crash of 2014 made a significant financial impact on the sub-Saharan nation, and the government has since been working to transition from being a state-led, oil-funded economy and seeks economic growth from the private sector. Whatever comes next, it’s expected that people will continue to move to the port city from Angola’s rural areas, bringing the population up by 62% and into megacity status by 2050.

When factoring in adjacent suburbs, the greater Los Angeles region had a population of 12.5 million people in 2022, making it America’s second largest city. It’s not just population that makes this a megacity. Its GDP for 2022 was approximately $712 billion — more than that of neighbouring states or even several countries in Europe.

This megacity hasn’t seen the same shocking rates of growth as many of the other locations on this list, though its population is expected to increase by around 20% to 15 million in 2050.

Considered one of China’s four “first tier cities”, Guangzhou has developed into a megacity boasting some of the country’s best infrastructure and one of its strongest economies. In 2022 it had a GDP of around $380 (£304bn). This of course translates into being one of the fastest growing locations, with the population skyrocketing from 3 million in 1990 to 14 million today.

That said, recent reports show that the population has declined slightly in Guangzhou, with speculation that a lack of jobs has caused people to look elsewhere for work. However, the long-term projections for 2050 estimate the megacity will continue increase its population over the next few decades.

With a 2022 population of 14.1 million and a projected population of 15.6 million in 2050, Tianjin in north-eastern China is very similar to Guangzhou in population size. However, by GDP it ranks much lower, worth $220 billion (£176bn) in 2022.

Like other Chinese megacities, Tianjin has drawn in rural migrants, and benefits from its proximity to Beijing. In fact, Chinese president Xi Jinping announced in 2014 the cities of Beijing, Tianjin and nearby Hebei would become the Jing-Jin-Ji Region, working together to coordinate development. The combined population of this conurbation is around 120 million people.

The south-central city of Hyderabad has been an emerging megacity, reaching the 10 million population mark only recently. It’s often used as a representative example of the globalisation and rapid rural-to-urban growth among India’s megacities.

Drawing in foreign investment from the IT, life sciences and infrastructure industries looking for workers, it’s home to a significant portion of the state’s population. It also has a flourishing pharmaceuticals industry, contributing to 40% of the bulk drug manufacturing in India, and looks to be a hotspot for data centres, even attracting investments from the likes of Amazon. All these new opportunities will continue to generate new jobs, with the population likely to reach 16.2 million by 2050.

Of all the megacities forecasted for 2050, Dar es Salaam will see the most extreme population growth at 118%, going from just 7.5 million in 2022 to 16.4 million.

The sub-Saharan future megacity is a transportation hub for cities across the region, and thus has become a centre for trade. However, Tanzania as a whole is experiencing rapid population growth, seeing an increase of 37% over the last decade due to its high fertility rates and increasingly lower infant mortality rates. The country is struggling with issues of poverty and economic mobility, and Dar es Salaam is not immune to these challenges. In 2017, almost 70% of the city’s population lived in informal or slum housing, Reuters reported.

Tanzania is one of eight countries estimated to contribute to half of the increase in global population in the next three decades.

The complete opposite is happening in Osaka, home to 19 million people. Its population will likely decrease by 12% over the next few decades. This is largely due to Japan’s lower birth rates and ageing population — the latter phenomenon is often concentrated in the suburbs of cities like Osaka.

This is an issue the country as a whole has been facing over the last two decades, and of the developed nations, it’s losing population most rapidly. However, Osaka’s dominance as a megacity still stands despite this. It has been ranked as one of the top economies in Asia, and contributes 4% of Japan’s GDP.

Combining its surrounding provinces, Buenos Aires is one of the largest cities in the Americas with a population of 15.4 million in 2022. A moderate increase, relatively speaking, is expected by 2050 to 17.4 million people.

Like many other existing megacities on this list, Buenos Aires is a major driver of the national economy. Nearly 40% of the country’s population live here and the city has long accounted for a significant portion of Argentina’s GDP.

India’s southern states account for 35% of its $7 trillion (£5.6tr) economy, and Chennai is known as the gateway to this region. Located on the south-eastern coast and capital of the Tamil Nadu state, this megacity is home to 11.6 million people and a hotbed of manufacturing.

The Tamil Nadu government is working with the World Economic Fund (WEF) to set up a centre for advanced manufacturing in Chennai, which would target the electronics, automobile and other industries. It will also partner with academia and research facilities to advance the city’s capabilities for making newer technologies like semiconductors, hydrogen and solar panels. It’s no surprise projections suggest it will add another 6 million people to its population by 2050.

Straddling both Europe and Asia, Istanbul's geography contributes to its megacity status, propelling the city beyond the Turkish capital Ankara. Istanbul generates around 30% of the country's GDP, while Ankara is responsible for little more than 9%. Istanbul's population of 15.7 million is also around three times larger than Ankara’s.

Over the last 100 years Turkey has become increasingly urbanised with more than three-quarters of its population living in cities compared to 25% at the start of the 20th century. Immigration from surrounding countries also had an impact in the 1990s, and both Istanbul and Ankara saw their populations grow as much as 2-3% year on year through the noughties. However, those rates have started to slow over the last 10 years. With a modest increase of 18%, Istanbul's current population of 15.7 million will continue to grow, but at increasingly slower rates. 

Located at the confluence of the Yangtze and Jialing Rivers, Chongqing ranks as the largest city in China by area. What’s more impressive is that the sprawling city technically dates back to only 1997 when it split from the Sichuan province — partly due to the construction of the nearby Three Gorges Dam, which displaced around 1.5 million people. This effectively kickstarted rural-to-urban migration, further fuelled by foreign investment that saw the development of offices and factories and a plethora of job opportunities.

While Chongqing has seen rapid development and growth into a megacity, by 2050 the city’s population of 17 million is only projected to grow by just shy of 2 million people.

Just over 13 million people live in Bangalore, but by 2050 the city is expected to pass the 20 million population mark. Much of this is due to the city’s well-established tech industry, home to big international players like Texas Instruments, Amazon and Samsung. Positioning itself as the “Silicon Valley of India”, the city boasts complementary institutions including prestigious engineering and science universities and research centres.

Rapid economic growth has come with a cost, though. Much of the city’s lauded green spaces have succumb to development, yet there are still housing shortages, and the public transportation system lacks capacity. 

Over the next few decades the population of Lahore will increase by more than 50% from 13.6 million in 2022, retaining its status as Pakistan’s second largest city. Lahore’s growth rate has been nearly double that of the national average, and much of the previous and predicted population increases are due to internal migration as people seek better education and healthcare. The city is home to several universities, a strong manufacturing industry and, increasingly, job opportunities in knowledge-based service industries.

However, Lahore’s dizzying rate of development, much of it left unchecked by governmental planning, saw built-up areas almost double from 1999 to 2011. This has contributed to major urban sprawl, traffic congestion and informal settlements that some fear will hamper future economic growth.

Manila is also expected to see a population increase of more than 50% by 2050. Currently 14.5 million people live in the capital city, which is a major contributor to the national economy, generating at least a third of the Philippines’ GDP.

This concentrated wealth has created significant disparities within the country, with per capita income in Manila around 2.75 times higher than the national average. It’s no surprise internal migration is the predominate factor for the city’s rapid growth, both past and predicted.

America’s largest city, just shy of 19 million people lived in New York in 2022. While the US capital may be Washington, D.C., the Big Apple dominates in almost every other way. It’s the nation’s centre for finance and banking, with much of the media and technology industries based there too. The city’s estimated GDP is $2.5 trillion (£2tr) for 2023, according to the World Economic Forum, which is more than the GDP of Canada or Italy. 

While the city does expect continued growth, reaching nearly 23 million by 2050, these rates are actually lower than those seen in previous decades. Four of the city’s five boroughs are expected to reach historical highs, with the Bronx and Brooklyn likely to see the most growth. Manhattan, predicted to see the smallest growth rates, peaked in population in 1910.

By 2050, Kolkata (formerly Calcutta) will have India’s third largest population, and currently around 15 million people live in the megacity near the Bangladesh border. In the late 19^th century, the population was a mere 200,000 and it has skyrocketed ever since, first due to its significance in the British Empire, and later from post-independence migration. Over the 20^th century, infrastructure has not kept pace with this growth and with the population projected to increase to 23.4 million, many are uncertain how the city will cope with a lack of infrastructure, especially considering the future impacts of climate change.

By 2050, Beijing is expected have approximately the same population as Kolkata. However, its 2022 population is already at 21.4 million—and last year marked the first time in nearly 20 years the city saw a population decline. This is likely due to lower birth rates, and reflects a wider trend in China, although others point to a high cost of living making the issue more pronounced in Beijing. It closely trails Shanghai in having the highest GDP and the highest housing costs across all of China’s megacities.

The capital city saw rapid growth during the second half of the 20^th century, going from the fourth largest to the second in just one decade. But that gruelling pace of urbanisation is unlikely to continue with such (comparatively) small growth projections of 11% for 2050.

Similarly, Sao Paulo rapidly industrialised in the 20th century, overtaking Rio de Janeiro in population, and eventually passing the 20-million population mark. While 22.5 million people lived in the city in 2022, that growth has begun to slow over the last 20 years and a small increase of 7% is projected through to 2050. This reflects wider trends in Brazil where population growth has slowed, though not declined, in recent years.

However, Sao Paulo still has an outsized impact on the country's economy, accounting for 20% of its GDP, with 10% of Brazil’s population and home to the most workers. More than half of the population lives in the city, with the rest comprising the wider metropolitan region, and as seen in Rio de Janeiro, around 11% live in favelas.

Currently the second largest city in the Americas, Mexico City has a population of just over 22 million people. Over the next few decades it is projected to grow by about 16% to overtake Sao Paulo by 2050. 

Much of the city's growth came from internal rural-to-urban migration, which saw the population shoot up from just 3 million in the 1950s to 14 million by the 1980s. It's also responsible for around 17% of the country's total GDP, and is home to the federal government making it Mexico's cultural, economic and political hub. 

However, like many of the cities on this list, it too suffers from housing shortages, crippling traffic congestion and associated air population, as well as increasingly overdrawing its water supplies.

With its location on the Arabian Sea, Karachi is Pakistan’s major port city and home to much of its manufacturing capacity. Not surprisingly, it accounts for more than 20% of the country's GDP.

The city’s previous population growth has been attributed to mass migrations following the partition of India and Pakistan, as well as refugees from Afghanistan and Bangladesh. Nearly 17 million people live in Karachi and it has struggled to accommodate much of this growth. As much as half of the population is estimated to live in informal settlements lacking clean water and electricity.

On top of that, it is expected to be one of the fastest growing cities worldwide. By 2050, Karachi is projected to be among the top 10 most populous megacities in the world.

With a population of around 300,000 people in the 1950s, Lagos has seen some of the most extreme growth rates and development as it grew into the city of 15.5 million people it is today. And it’s not likely to slow down. Over the next few decades Lagos is expected to see a population increase of 82% by 2050.

While this won’t make it the most populous city in the world at that time, there are estimates it could reach that title eventually. By 2100 Lagos is projected to have a population of as much as 100 million, more than both California and Britain.

Rural migration and higher birth rates are major contributors to Lagos’ booming growth, and much of the development has resulted in sprawl that is taxing the city’s infrastructure and creating wide economic disparities.

Similar rapid development happened in Kinshasa, where only 20,000 people lived in 1920, and now 100 years later its population is just shy of 16 million. This has also resulted in a sprawling city with vast inequalities, especially in the peripheries.

The Democratic Republic of the Congo is set to see even more migration to the capital city, by as much as 84% by 2050, making it the most populated city in all of Africa. By some estimates, about 40% of all humans will be African by 2100.

There is much concern over the ways cities like Kinshasa and Lagos will continue to develop, whether it is sustainable, and how to ensure economic growth, infrastructure and housing keep pace.

With a current population of 28.7 million people, Shanghai is China’s biggest city by population and will continue to be so through to 2050, according to projections.  

The city has seen major economic growth over the last 30 years, and makes up nearly 4% of China’s GDP — quite a feat considering the country has seven other megacities and Shanghai only accounts for roughly 0.1% of the country’s land mass.

Part of its success is due to its location, where the Yangtze River meets the East China Sea. When the Chinese government opened the country to foreign investment the city became a trade hotspot awash in real estate development that ranged from iconic seafront skyscrapers to sprawling suburbs (pictured).

Currently India’s second largest city with a population of 21 million, Mumbai has long been a preferred destination for migration with its low-skilled jobs and lower cost of living in informal settlements. It’s estimated more than 1 million people live in Dharavi (pictured), the city’s largest squatter settlement, many who are second generation.

However, Mumbai has actually seen its population growth slow over the last 20 years, with the suburbs offering less expensive housing and the birth rate dropping. Others point out a lack of jobs and new industries in the megacity, with some ministers blaming the city’s failure to invest in infrastructure and observing that Mumbai is losing businesses to India’s newer megacities.

In 2022, Egypt celebrated the milestone of its national population reaching 100 million. Fertility rates are high across the country where people are increasingly likely to live in cities.

With a population of 21.8 million Cairo has the largest share of the country’s population, developing further into the desert as the congested city grows. Similar to Mumbai in both current and projected population, Cairo also has large informal settlements that are absorbing much of the growth.

Like many cities on this list, Greater Cairo has an outsized role in Egypt’s economy, accounting for nearly half of national GDP.

The projections for 2050 show Tokyo having the same population as Cairo, however that's because a 12% decrease in its population is expected. Currently 37.3 million people live in Japan's capital, which, in true megacity style, accounts for around 20% of the country's GDP. 

As seen in Osaka, steep declines in the country's population due to lower birth rates are already taking place after its population peaked in 2008, and Tokyo is not immune to these losses. Despite these demographic changes it is expected to be the third largest megacity worldwide in 2050. 

Since its independence from Pakistan in 1971, the population of capital city Dhaka has soared from 1 million to 22.6 million, as it grew into a megacity and an economic hub. The city’s economy accounts for 35% of the country’s GDP, much of which is attributed to internal migration. Previously only 9% of the country lived in urban areas and that’s now grown to more than a third.

While Dhaka has invested in infrastructure over this period, and seen strong economic growth of late, much of that is highly concentrated in wealthier areas. Further creating issues, much of the development in poorer neighbourhoods is done without planning, creating slum-like conditions for many of the city’s residents who’ve left villages for a better life.

Migration continues at a rapid pace with estimates that as many as 400,000 people move to the city from rural areas each year. By 2050, the population is projected to be more than 34 million.

By 2050 projections, Delhi will have overtaken Tokyo as the world’s biggest city by population. The United Nations expects this will actually happen a lot sooner – possibly by 2028.

India’s capital has experienced one of the fastest urban expansions, doubling its land mass in just 20 years between 1991 and 2011, converting the surrounding rural area for more housing as people migrated for job opportunities. It’s long had one of the highest per capita incomes in India, recently 2.6 times higher than the national level.

However, traffic congestion, pollution and a housing crisis are already very real issues for Delhi. An estimated 6.75 million people live in poor housing that the city defines as: 695 slum settlements, 1,797 unauthorised colonies and 362 urban villages.

Policy makers question whether the city is prepared to accommodate the dramatic growth that bring its population to nearly 50 million by 2050.