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Rio de Janeiro, 
Brazil
9,500,336 people lived in Rio de Janeiro in 2025. It is the 35th largest of the world's 12,138 cities, and the 2nd largest in Brazil.
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 Rio de Janeiro'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 Rio de Janeiro grew
For every 10 people in Rio de Janeiro in 1975, there were 16.2 in 2025.
On the UN's projection it will have 9.3 million people in 2050.
projected (after 2025) · how sure the UN is: high moderate low
How to read this: one column every five years, 1975 to 2050; its height is the number of people. Hatched columns are the UN's projection. The thin strip beneath says how sure the UN is of each figure: the stronger the colour, the surer. A blank means the place was not on the UN's list of cities that year.
People · your family's years · 1975 to 2050
Rio de Janeiro through your family’s years
Put in the years your family were born. You’ll see how many people lived in Rio de Janeiro in each of those years, and when each of them turned 30.
Brazil · every city · 2025
Where it is
How to read this: Rio de Janeiro is the dot in colour with a ring around it. The grey dots are the other cities of Brazil in 2025, 356 in all, led by São Paulo, each drawn with an area that matches its people. Countries next door are outlines only.
Area and built-up land · km²
How much land it covers
In 2025, Rio de Janeiro covered 1,260 km², and buildings, roads and other built-up land covered 343 km² of it. That is 36 m² of built-up land for each person, about a square 6 by 6 metres. Since 1975, its built-up land has grown by 74%, and its people have grown by 62%.
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 Brazil
Its share of Brazil
Of every 100 people in Brazil in 2025, 4 lived in Rio de Janeiro, which is 9.5 million people.
How to read this: shrink Brazil to 100 people and this is what you get. The coloured squares are the ones who would live in Rio de Janeiro; the grey ones are everybody else, in other cities, in towns and out in the country.
Ranked by people · 2025
Cities of a similar size
In the world, 2025
- 31 Bogotá Colombia10,624,315
- 32 Lima Peru10,580,241
- 33 London United Kingdom10,416,420
- 34 Hajipur India9,941,510
- 35 Rio de Janeiro9,500,336
- 36 Paris France9,381,921
- 37 Hyderabad India9,190,795
- 38 Tehran Iran9,174,964
- 39 Taipei Taiwan9,136,792
In Brazil, 2025
- 13 São Paulo18,949,790
- 35 Rio de Janeiro9,500,336
- 105 Belo Horizonte4,162,814
- 124 Recife3,691,196
- 149 Fortaleza3,244,260
- 158 Salvador3,135,157
- 200 Curitiba2,475,352
- 214 Goiânia2,320,596
- 217 Manaus2,277,352
How to read this: names are in order of size, the leading number being each city's rank among all 12,138 in 2025; the bars share a scale within a list. A jump in the ranks means a city under 300,000 people, which is not given a page here.
Apparatus
Sources and method
The figures for Rio de Janeiro 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 Rio de Janeiro 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