Cambridge (CIE) IGCSE Geography
Population Density & Distribution
The Big Idea: People aren't spread evenly across the Earth — some places are packed (Singapore, Monaco) and some are almost empty (Mongolia, Greenland). This happens because of a mix of physical factors (climate, relief, water, resources, soil) and human factors (jobs, government investment, services, culture) that make some places easy and attractive to live in, and others hard.
1. What Density and Distribution Actually Mean
These two words get mixed up constantly in exams, so let's nail the difference right away using an analogy.
Think of it like a classroom
Density is like asking: "On average, how many students are squeezed into each square metre of this classroom?" It's one single number that describes crowding.
Distribution is like asking: "Where in the classroom are the students actually sitting?" Are they all bunched near the door, spread evenly, or clustered in one corner? It's about the pattern, not a number.
So a country can have a "medium" density on average, but a very uneven distribution — think of Egypt, where almost everyone lives along the thin strip of the Nile River, while the surrounding desert is nearly empty. The average density number alone would completely hide that pattern.
The Density Formula
Formula
Population Density = Total Population ÷ Total Area (km²)
In plain English: count everyone living somewhere, then divide by how much land they're living on. The bigger the number, the more crowded it is.
The "total area" can be measured at very different scales — a small region, an entire country, or even a whole continent — so always check which scale a question is asking about before you answer.
26,337
people per km² in Monaco (2022) — the world's highest density
< 0.2
people per km² in Greenland (2022) — the world's lowest density
59.27
people per km² — the average world population density (2022)
Common Mistake
Students often use "density" and "distribution" as if they mean the same thing. Remember: density is a
number (crowdedness), distribution is a
pattern (where people are located). An exam question asking you to "describe the distribution" wants you to talk about location and pattern — not just state a density figure.
Practice Question 1
Try it yourself
A country has a population of 20 million people and a total area of 500,000 km². Calculate its population density, and explain in one sentence what this number tells you.
Practice Question 2
Try it yourself
Explain why two countries could have the exact same population density figure, but look completely different on a population distribution map.