Topics
Blida, 
Algeria
663,070 people lived in Blida in 2025. It is the 818th largest of the world's 12,138 cities, and the 3rd largest in Algeria.
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 Blida'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 Blida grew
For every 10 people in Blida in 1975, there were 55 in 2025.
On the UN's projection it will have 765,120 people in 2050. It passed 250,000 people between 1995 and 2000.
projected (after 2025) · how sure the UN is: high moderate low
How to read this: each column is one of the UN's five-yearly estimates, 1975 through 2050, and taller means more people. Where a column is hatched the year has not happened yet. The strip under the columns is the UN's own confidence in each figure, palest where it is least sure; where it is blank the city was not on the list at all.
People · your family's years · 1975 to 2050
Blida through your family’s years
Put in the years your family were born. You’ll see how many people lived in Blida in each of those years, and when each of them turned 30.
Algeria · every city · 2025
Where it is
How to read this: every dot is one of the 109 cities in Algeria in 2025, and a dot's area is how many people live there, the biggest being Algiers. The ringed dot in colour is Blida; 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, Blida covered 95 km², and buildings, roads and other built-up land covered 22 km² of it. That is 34 m² of built-up land for each person, about a square 6 by 6 metres. Since 1975, its built-up land has grown to 3.4 times its size, and its people are 5.5 times as many.
How to read this: each pale square is the city's whole area, the strong square inside it the part that is built on; one scale for all three, so a bigger square is more land. Hatched is the UN's projection.
Of every 100 people in Algeria
Its share of Algeria
Of every 100 people in Algeria in 2025, 1 lived in Blida, which is 663,070 people.
How to read this: 100 squares stand for everyone in Algeria, one square for every 100th person. Count the coloured ones and you have Blida's share; the grey remainder live somewhere else in the country.
Ranked by people · 2025
Cities of a similar size
In the world, 2025
- 814 Changwon South Korea665,772
- 815 Fushun China665,286
- 816 Anand India664,789
- 817 St. Louis United States663,392
- 818 Blida663,070
- 819 Leiyang China662,696
- 820 Wuppertal Germany662,663
- 821 Kannur India662,128
- 822 Jhansi India662,059
In Algeria, 2025
- 148 Algiers3,246,400
- 434 Oran1,192,410
- 818 Blida663,070
- 998 Boumerdes550,700
- 1016 Djelfa542,414
- 1063 Constantine519,932
- 1168 Annaba474,367
- 1566 Batna366,415
- 1636 Setif349,825
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 Blida 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 Blida 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