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Buenos Aires, 
Argentina
14,017,736 people lived in Buenos Aires in 2025. It is the 21st largest of the world's 12,138 cities, and the largest in Argentina, 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 Buenos Aires's own can differ widely. What counts as a city here.
Verified 2026-09-30 · 73 canaries
People · every five years · 1975 to 2050
How Buenos Aires grew
Count 10 people in Buenos Aires in 1975 and the same count gives 16.4 in 2025.
On the UN's projection it will have 14.2 million people in 2050. It passed ten million people between 1985 and 1990.
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
Buenos Aires through your family’s years
Put in the years your family were born. You’ll see how many people lived in Buenos Aires in each of those years, and when each of them turned 30.
Argentina · every city · 2025
Where it is
How to read this: Argentina and its 77 cities in 2025, each a dot whose area is its number of people. Buenos Aires is ringed, in colour; the other cities are grey. Neighbouring countries are outlines.
Area and built-up land · km²
How much land it covers
In 2025, Buenos Aires covered 2,164 km², and buildings, roads and other built-up land covered 710 km² of it. That is 51 m² of built-up land for each person, about a square 7 by 7 metres. Since 1975, its built-up land has grown by 63%, and its people have grown by 64%.
How to read this: pale is the whole of the city's land; the stronger square inside it is what is actually built on. The three are drawn to the same scale, so a larger square really is more land, and hatching means the year is the UN's projection rather than a count.
Of every 100 people in Argentina
Its share of Argentina
Of every 100 people in Argentina in 2025, 31 lived in Buenos Aires, which is 14.0 million people.
How to read this: 100 squares stand for everyone in Argentina, one square for every 100th person. Count the coloured ones and you have Buenos Aires's share; the grey remainder live somewhere else in the country.
Ranked by people · 2025
Cities of a similar size
In the world, 2025
- 17 Lahore Pakistan15,156,430
- 18 Istanbul Türkiye15,014,763
- 19 Moscow Russia14,524,753
- 20 Ho Chi Minh City Vietnam14,052,713
- 21 Buenos Aires14,017,736
- 22 New York City United States13,920,148
- 23 Shenzhen China13,878,396
- 24 Bengaluru India13,187,098
- 25 Osaka Japan12,964,145
In Argentina, 2025
- 21 Buenos Aires14,017,736
- 346 Cordoba1,460,491
- 445 Rosario1,151,717
- 495 Mendoza1,027,849
- 541 San Miguel de Tucumán959,565
- 720 La Plata742,952
- 879 Mar del Plata614,979
- 881 Salta613,956
- 1198 San Juan464,466
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 Buenos Aires 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 Buenos Aires 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