Topics
Bangkok, 
Thailand
Krung Thep Maha Nakhon
18,180,280 people lived in Bangkok in 2025. It is the 14th largest of the world's 12,138 cities, and the largest in Thailand, where it is the capital.
The UN measures every city in the world the same way, by where the buildings are rather than where the boundary runs, so this figure and Bangkok's own can differ widely. What counts as a city here.
In its own language: Krung Thep Maha Nakhon.
Verified 2026-09-30 · 73 canaries
People · every five years · 1975 to 2050
How Bangkok grew
For every 10 people in Bangkok in 1975, there were 49.8 in 2025.
On the UN's projection it will have 20.5 million people in 2050. It passed ten million people between 2000 and 2005.
projected (after 2025) · how sure the UN is: high moderate low
How to read this: read it left to right, 1975 to 2050, one column every five years, the height being people. Hatching marks the projected years. Below, a strip of the UN's confidence: strong colour where the census maps are recent and detailed, pale where they are not, blank where the place was not counted as a city.
People · your family's years · 1975 to 2050
Bangkok through your family’s years
Put in the years your family were born. You’ll see how many people lived in Bangkok in each of those years, and when each of them turned 30.
Thailand · every city · 2025
Where it is
How to read this: every dot is one of the 56 cities in Thailand in 2025, and a dot's area is how many people live there. The ringed dot in colour is Bangkok; the grey dots are the rest. The outlines around them are neighbouring countries.
Area and built-up land · km²
How much land it covers
In 2025, Bangkok covered 2,661 km², and buildings, roads and other built-up land covered 680 km² of it. That is 37 m² of built-up land for each person, about a square 6 by 6 metres. Since 1975, its built-up land has grown to 5.2 times its size, and its people are 5 times as many.
How to read this: the outer pale square stands for all the land the city covers, and the solid square inside it for the part with buildings, roads and the like on it. All three squares share a scale, so you can compare them by eye. A hatched one is a year the UN has projected.
Of every 100 people in Thailand
Its share of Thailand
Of every 100 people in Thailand in 2025, 25 lived in Bangkok, which is 18.2 million people.
How to read this: 100 squares stand for everyone in Thailand, one square for every 100th person. Count the coloured ones and you have Bangkok's share; the grey remainder live somewhere else in the country.
Ranked by people · 2025
Cities of a similar size
In the world, 2025
- 10 Seoul South Korea22,490,482
- 11 Karachi Pakistan21,422,590
- 12 Mumbai India20,203,056
- 13 São Paulo Brazil18,949,790
- 14 Bangkok18,180,280
- 15 Mexico City Mexico17,734,212
- 16 Beijing China17,013,303
- 17 Lahore Pakistan15,156,430
- 18 Istanbul Türkiye15,014,763
In Thailand, 2025
- 14 Bangkok18,180,280
- 864 Chiang Mai626,629
- 1387 Hat Yai407,059
- 1465 Phuket389,376
- 1500 Lop Buri378,160
- 1943 Chon Buri297,276
- 2527 Nakhon Pathom232,416
How to read this: the number before each name is its place among all 12,138 cities in the world in 2025; bars are people, on one scale per list. Only cities that reach 300,000 people have a page here, so a gap in the numbers is a smaller city.
Apparatus
Sources and method
The figures for Bangkok are the UN's own, at five-year steps: an estimate for each of 1975 to 2025, then projection to 2050. Projected years are drawn hatched, and the UN publishes no range of uncertainty for a city. What a city means here, how the UN measures one, and why that number can differ from the one Bangkok publishes about itself: how the figures here are put together.
Sources: UN WUP 2025 · Natural Earth · flag-icons. Every source, its licence and how to cite it →
Verified 2026-09-30 · 73 canaries