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Patna, 
India
3,309,383 people lived in Patna in 2025. It is the 141st largest of the world's 12,138 cities, and the 18th largest in India.
That figure counts the whole built-up area, not the area Patna governs, so it may be far from the number the city publishes about itself. How the UN measures a city.
Verified 2026-09-30 · 73 canaries
People · every five years · 1975 to 2050
How Patna grew
Count 10 people in Patna in 1975 and the same count gives 37.3 in 2025.
On the UN's projection it will have 3.9 million people in 2050. It passed a million people between 1975 and 1980.
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
Patna through your family’s years
Put in the years your family were born. You’ll see how many people lived in Patna in each of those years, and when each of them turned 30.
India · every city · 2025
Where it is
How to read this: India and its 2,054 cities in 2025, each a dot whose area is its number of people (the largest is New Delhi). Patna 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, Patna covered 257 km², and buildings, roads and other built-up land covered 51 km² of it. That is 16 m² of built-up land for each person, about a square 4 by 4 metres. Since 1975, its built-up land has grown to 3.5 times its size, and its people are 3.7 times as many.
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 India
Its share of India
Of every 1,000 people in India in 2025, 2 lived in Patna, which is 3.3 million people.
How to read this: 1,000 squares, one for every 1,000th person in India; the coloured squares live in Patna. The grey rest live in other cities, in towns or in the countryside.
Ranked by people · 2025
Cities of a similar size
In the world, 2025
- 137 Jinan China3,472,980
- 138 Changsha China3,457,508
- 139 Medellín Colombia3,350,384
- 140 Changchun China3,349,934
- 141 Patna3,309,383
- 142 Nanchang China3,299,773
- 143 Nanning China3,288,636
- 144 Quanzhou China3,286,129
- 145 Washington, D.C. United States3,270,018
In India, 2025
- 97 Kanpur4,329,973
- 110 Jaipur4,071,754
- 119 Varanasi3,858,863
- 136 Indore3,476,423
- 141 Patna3,309,383
- 147 Nagpur3,257,841
- 156 Kalyan-Dombivli3,163,424
- 162 Kollam3,074,562
- 166 Thiruvananthapuram2,946,119
How to read this: the figure in front of a name is where that city stands among the 12,138 cities the UN counted in 2025, and each bar is its people, on one scale per list. Numbers are missing where a city has fewer than 300,000 people and so has no page of its own.
Apparatus
Sources and method
The figures for Patna 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 Patna 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