The population of Tokyo – Greater Tokyo Area is nearly 37 million people, the most populous urban area in the world, accounting for nearly 1/3 of Japan's population.
Introduction and Scope of Greater Tokyo Area
The Greater Tokyo Area includes Tokyo Metropolis and three neighboring prefectures: Kanagawa, Saitama and Chiba. It is the world's largest metropolitan area by population, with nearly 37 million people – about one-third of Japan's population.
The region covers a total area of approximately 13.560 km², extending from central Tokyo with its special wards (23 wards) to satellite cities in Kanagawa, Saitama, Chiba and some peripheral areas.
This article will analyze in detail the population situation of the Greater Tokyo Area based on the latest official figures, focusing on the following aspects: (1) Total population and change trends in the past 5–10 years; (2) Age and gender structure; (3) Population density (4) Population distribution in major urban areas in each province; and (5) Factors affecting population change (natural increase/decrease, domestic and international migration).
1. Total Tokyo population and change trend (recent 5–10 years)
As of the 2020 Census, the total population of the Greater Tokyo Area (Tokyo, Kanagawa, Saitama, Chiba) was 36.914.176. This is an increase of about 800 people compared to 2015 and an increase of about 1,3 million people compared to 2010, reflecting a slight population growth trend in the 2010–2020 decade.
Specifically, during the 2015–2020 period, Tokyo's population increased sharply by +3,9%, Kanagawa by +1,2%, Saitama by +1,1%, and Chiba by +1,0%. This increase was mainly due to higher in-migration than out-migration and partly due to a slightly positive natural increase in the period before 2020 in Tokyo (see section 5).
However, after 2020, the population trend began to slow down. According to the mid-term population estimate, from 2020 to 2022, the population of the whole region decreased slightly (about 0,11%, equivalent to a decrease of ~41 thousand people). Tokyo recorded its first population decrease (decreased by about 9.400 people, equivalent to -0,07% in 2021–2022), and Kanagawa, Saitama, and Chiba prefectures also decreased slightly (decreased by 0,05–0,29%).
The main reasons for Tokyo's population decline are the COVID-19 pandemic in 2020–2021, which caused a portion of the population to leave the capital (a temporary trend) and reduced inward migration; at the same time, population aging led to a higher number of deaths than births (part 5 will analyze in detail).
By 2023, Tokyo's population began to increase slightly again, while the remaining prefectures continued their downward trend, leaving the total regional population largely stable around 36,8–37 million.
Overall, Tokyo (the capital) has always been the most populous locality. In 2020, Tokyo reached 14,05 million people – the highest among the prefectures. Kanagawa (9,23 million), Saitama (7,34 million) and Chiba (6,28 million) are all among the most populous prefectures in Japan (ranked 2nd, 5th and 6th nationwide).
During the 2010–2020 period, Tokyo contributed the majority of the region's population growth (an increase of nearly 0,9 million people), while Kanagawa, Saitama, and Chiba each increased by only 0,06–0,11 million. This shows the increasing concentration of population in the capital.
However, entering the 2020s, the growth rate has slowed significantly and the Greater Tokyo Area is forecast to enter a period of population saturation and decline in the coming years, in line with the general trend in Japan.
2. Age and gender structure of Tokyo's population
The Greater Tokyo Area's population has a younger age structure than the national average, although it is still aging rapidly. As of 2020, the proportion of elderly people (≥65 years old) in the entire region was about 25–26%, lower than the national average of 28,6%.
In particular, Tokyo has the youngest population: only about 23% of Tokyo's population is 65 years or older – the lowest proportion among Japan's prefectures (compared to the oldest prefecture, Akita, at ~37,5%). Meanwhile, neighboring prefectures such as Chiba and Saitama have a slightly higher proportion of people ≥65 years old (approximately 27–28%), due to fewer young immigrants than Tokyo. Kanagawa is in the middle, at around 26%.
In contrast, the young population (under 15 years old) accounts for about 12% of the total population of the region – similar to the national average (about 12% in 2020). The proportion of children in Tokyo (~13% if 0–17 years old is taken into account ~14%) is slightly higher due to the large number of young people living there, while in prefectures such as Chiba, Saitama the proportion is around 12–13%.
The working-age group (15–64 years) accounts for about 59–61% of the region's population, slightly higher than the national average of 59,5%. Tokyo has the highest proportion of working-age people (about 63–64%), reflecting the capital's attraction of many young workers from elsewhere. This age structure shows that Tokyo and the metropolitan area remain a dynamic economic center with an abundant workforce, but the proportion of the elderly is steadily increasing.
On gender structure, the Tokyo region's population has more females than males, similar to the general trend (due to higher female life expectancy). In 2020, the entire region was estimated to have about 49% males and 51% females. Tokyo alone has about 6,90 million males and 7,15 million females (females account for ~50,9%); Saitama has ~3,65 million males and ~3,69 million females.
The gender gap is mainly concentrated in the elderly group (women live longer), while in the young and middle-aged groups, the male/female ratio is quite balanced. Notably, Tokyo attracts many young single workers of both men and women, so in the central area of Tokyo, some inner-city districts may have a slightly higher male ratio (due to the large number of young men coming to work). However, in the whole region, women have a slight advantage, especially in the elderly group.
3. Population density of the whole region and each province
The Greater Tokyo Area is a very densely populated metropolitan area. On average, the population density of the entire region is about 2.700 people/km² (2020), more than 8 times higher than the national average of Japan (~340 people/km²). However, the density is unevenly distributed among regions:
Tokyo (Capital): Highest density, reaching about 6.414 people/km² (2022). In particular, the 23 central districts of Tokyo have extremely high density, an average of nearly 15.000 people/km². Some inner-city districts such as Toshima, Nakano, Arakawa even exceed 20.000 people/km². Tokyo's density is high due to the concentration of a large population in a small area (Tokyo is only ~2.190 km², of which the majority of the population is concentrated in the inner-city urban area).
Kanagawa: Density is approximately 3.822 people/km² – the second highest after Tokyo. Kanagawa Prefecture (2.416 km²) is home to the densely populated cities of Yokohama and Kawasaki (see section 4), making the prefecture's average density quite high. Kanagawa's coastal and urban areas are densely populated, while the mountainous western regions are less populated.
Saitama: Density is about 1.932 people/km². Saitama (3.798 km²) has a lower average density due to its large rural area in the north. However, the southern part of the prefecture bordering Tokyo (cities such as Saitama, Kawaguchi, Kasukabe…) also has a density of up to 5.000–10.000 people/km².
Chiba: Density is about 1.215 people/km² – the lowest of the four prefectures. Chiba (5.157 km²) has the largest area and includes many rural, mountainous areas in the east. The population is mainly concentrated in the west (bordering Tokyo, around Tokyo Bay) and some coastal cities, so the overall density of the prefecture is not as high as the other prefectures.
In general, population density decreases from central Tokyo to the periphery. The urban core (Tokyo 23 Wards, Yokohama, Kawasaki) is extremely dense, while the more remote areas such as northern Saitama or eastern Chiba are considerably less dense.
This density difference reflects the process of urbanization: the population is concentrated near the economic and employment centers, while the population is dispersed farther away. However, compared to the international level, Greater Tokyo's average density of ~2.700 people/km² is still among the highest in the world for a metropolitan area of over 10.000 km².
4. Population distribution by major cities in the region
The Greater Tokyo Area includes several major cities. Below are representative cities and their populations, broken down by prefecture.
Tokyo Metropolis
The capital Tokyo is not a single “city” but consists of 23 special wards that make up the central urban area, along with many satellite cities and towns.
The 23-ward area is the center of Tokyo, with a total population of about 9,73 million people (2020). Of which, the most populous wards are Setagaya (~0,93 million), Nerima (~0,73 million), Ota (~0,73 million),... equivalent to large cities.
In addition to the 23 wards, Tokyo also has large suburban cities such as Hachiōji (~0,58 million), Machida (~0,43 million), Fuchū, Tama... These are satellite cities located in the west of Tokyo. The population is mainly concentrated in the inner city; the islands and mountainous areas far away from Tokyo (belonging to Ogasawara and Izu prefectures) are very sparsely populated (only a few thousand people). In general, the population center of Tokyo is in the central urban area where the density is very high, while the density in the suburbs gradually decreases.
Kanagawa Prefecture
Kanagawa has Yokohama, which is the most populous city in Japan (if not counting the 23 Tokyo wards as one city). Yokohama's population is about 3,75 million (2024), exceeding the total population of some prefectures (for example, Yokohama is larger than Shizuoka Prefecture with 3,61 million people). Yokohama is located just south of Tokyo, and is a major port and industrial city.
Kanagawa's second largest city is Kawasaki, located between Tokyo and Yokohama, with a population of approximately 1,54 million (2020). Kawasaki has a very high density (over 10.000 people/km²) due to heavy urbanization along the Tama River.
Third is Sagamihara (northwest of Kanagawa) with about 0,725 million people (2020) – this is a new city designated by ordinance in 2010.
Thus, Kanagawa has 3 cities with over half a million inhabitants, of which Yokohama plays the role of the prefectural administrative and port economic center, Kawasaki and Sagamihara are industrial and residential satellite cities of Tokyo. Kanagawa's population is mainly concentrated in the urban strip along Tokyo Bay (Yokohama, Kawasaki) and the corridor connecting to central Tokyo.
Saitama Prefecture
The largest city is Saitama (prefectural capital) with a population of about 1,32 million (2021). Saitama City was formed by the merger of the cities of Urawa, Ōmiya, Yono… and is now an important administrative-commercial city in the north of Tokyo.
In addition, Saitama has several cities with over 500 people such as Kawaguchi (~0,60 million) and Funabashi, which is actually in Chiba - will be discussed below, please adjust: Saitama has Kawaguchi (~0,60 million), Kawagoe (~0,35 million), Tokorozawa (~0,34 million).
These cities are located on the outskirts of Tokyo and have developed as “sleeping cities” (homes for people working in Tokyo). Saitama’s population is densely distributed in the south (bordering Tokyo) – for example, Kawaguchi City, bordering the capital, has ~0,60 million people in a small, high-density area.
Northern Saitama (bordering Gunma and Ibaraki) is less populated and more rural. The entire Saitama prefecture has a fairly even network of suburban areas, with no single city being too dominant except for Saitama City.
Chiba Prefecture
The capital city of Chiba has a population of about 0,98 million (2025), and is the administrative and educational center of the prefecture. However, the most populous city in the prefecture is Funabashi City (~0,65 million), located next to Tokyo and an important “sleeping” city (many residents work in Tokyo).
Other major cities in Chiba include Matsudo (~0,49 million), Ichikawa (~0,49 million), Kashiwa (~0,43 million) – all located in the west of the prefecture, bordering Tokyo. The eastern part of Chiba (Bōsō Peninsula) is more sparsely populated, with only a few mid-sized cities such as Kisarazu, Katsuura… and many agricultural towns.
Thus, Chiba's population is concentrated mainly in the western urbanized area (adjacent to the capital), forming a continuous population corridor from Tokyo across the Edogawa River to the cities of Chiba. The eastern and southern parts of Chiba have very low density, being mountainous and coastal areas.
In summary, the Greater Tokyo Area's population distribution has a "polycentric" characteristic: in addition to the central core of Tokyo's 23 wards, the extended metropolitan area includes many large satellite cities surrounding it. Yokohama in the south, Kawasaki in the southwest, Saitama City in the north, Chiba City in the east, and a series of other medium-sized cities, form an urban cluster connected to Tokyo. This is a super-urbanized area with a dense network of cities, ensuring that the Tokyo area continues to expand in space while maintaining economic and social cohesion.
5. Factors affecting population change
Population change in the Greater Tokyo Area is influenced by two main factors: natural increase/decrease (births and deaths) and migration (including internal and international migration).
(a) Natural increase/decrease
Like the general trend in Japan, the Tokyo region is experiencing natural decline due to deaths exceeding births. Japan's very low fertility rate (~1,3 children/woman) has led to a gradual decline in the number of children born.
In 2022, Japan’s birth rate is expected to be around 730.000, a record low, while the death toll is expected to reach 1,58 million—more than double the number of births. The Tokyo area, despite having a large population of childbearing age, is not immune to this trend.
In recent years, the number of births in the Tokyo area has not been enough to offset the number of deaths. For example, in 2021, the capital Tokyo alone saw about 107.000 births but 138.000 deaths (negative about 31.000).
Kanagawa, Saitama, and Chiba prefectures are also naturally negative due to aging populations: the number of people over 65 accounts for 25–28% of the population, so the number of deaths each year is very high, while the number of births is low due to the decreasing number of young women. As a result, negative natural increase has become a reality in all four prefectures. This explains why the total population of the region began to decline after 2020, despite the large inflow of migrants – due to natural loss (births < deaths) somewhat overpowering the mechanical increase (immigration).
(b) Internal migration (within the country)
The key factor that has helped Tokyo become a “population magnet” is the wave of migration from other regions. For decades, young people from all over Japan have come to Tokyo to study and find work, creating a steady stream of immigration to the metropolitan area.
According to the Ministry of Internal Affairs and Communications of Japan, in 2024, the Greater Tokyo Area recorded a net domestic immigration of +135.843 people (i.e., the number of people moving in minus the number of people leaving). In particular, Tokyo City (Tokyo-to) alone attracted +79.285 net immigrants in 2024 – a sharp increase compared to only +5.433 in 2021 during the pandemic.
Neighboring prefectures also had positive immigration: Kanagawa +26.963, Saitama +21.736, Chiba +7.859 (2024), showing that the entire Tokyo metropolitan area continues to attract residents from other regions.
The largest group of migrants is young people aged 15–29. In 2024, the Tokyo area will have +86.908 net migrants aged 20–24 and +32.065 net migrants aged 25–29 – mainly recent graduates and young workers.
On the contrary, there is a trend of elderly people moving out of Tokyo: the 55–69 age group has more people leaving the area than coming in (either by retiring to the countryside or moving to quieter suburbs). This explains why Tokyo is relatively “young” – it is constantly being replenished by young immigrants, while some of the elderly leave.
In addition, urbanization is spreading: some people tend to move from inner Tokyo to neighboring prefectures (Kanagawa, Saitama, Chiba) after starting a family to find more spacious housing. Therefore, we see that Kanagawa, Saitama, Chiba also have positive immigration - many people leave central Tokyo to settle in suburban cities in the region instead of leaving the region altogether. Overall, internal migration is the main driver of population growth in the Greater Tokyo area.
Although the COVID-19 pandemic temporarily reduced Tokyo's attractiveness (net immigration in 2021 was only +5 thousand), the influx of people has recovered strongly since 2022, almost reaching pre-pandemic levels. Tokyo is still the leading economic and cultural center, so it attracts human resources from all over - this is an advantage that helps the region maintain its population despite aging.
(c) International migration and immigration
The international element has become increasingly important in recent years. The Tokyo area is home to Japan's largest foreign community.
By the end of 2024, the total number of foreigners residing in Japan will be 3,77 million (~3% of the population) – a record high. Of which, Tokyo is in the lead with 738.946 foreigners (an increase of 11,4% compared to 2023) – accounting for 19,6% of the total number of foreigners in Japan.
Kanagawa (292.450 people) and Saitama (262.382) are also in the top 5 nationwide in terms of foreign population. Including Chiba, the entire Tokyo area is estimated to have about 1,3–1,4 million foreign residents (including workers, international students, permanent residents, etc.).
This increase comes from Japan's relaxed immigration policy in the face of labor shortages, as well as Tokyo's attractive position for foreigners. The largest nationalities in Tokyo are Chinese, Vietnamese, Korean... - notably, the Vietnamese population is growing the fastest, currently ranking 2nd with ~634 thousand in Japan, concentrated in Tokyo and its surrounding areas.
International immigration has made a positive contribution to slowing down the population decline: in the context of a decline in the Japanese population, the increase in the foreign community has partly compensated for the shortage. For example, in 2022–2023, while the Japanese population continued to decline, the foreign population increased for two consecutive years.
The impact of international migration is also reflected in the urban population structure: in some central Tokyo districts such as Shinjuku, foreigners account for up to 10% of the population. They are mainly young people of working age or studying abroad, contributing to the relative rejuvenation of the local population structure and providing a labor force for the economy. However, the proportion of foreigners in the total population of the region (~4-5%) is still small, so the general trend has not been reversed. The decisive factor is still how to increase the birth rate and maintain domestic immigration.
In summary, the current Greater Tokyo Area population is maintained stable mainly due to positive mechanical migration – both domestic and international – offsetting negative natural growth due to aging. Tokyo still plays a leading role in attracting people, especially young people, from other places to study and work.
However, in the medium and long term, if the low birth rate and aging trend do not improve, the Tokyo region will soon enter a period of absolute population decline as internal immigration declines (as other prefectures also lose people).
The Japanese government has implemented a number of policies to encourage births and redistribute the population, but the effectiveness is limited. It is forecast that by 2030–2040, the population of the Tokyo area may begin to decline significantly, although it will maintain its position as the world's most populous metropolitan area for the next few decades.
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