Population pyramids
Population pyramids are bar charts that show how many people of different ages are living in a place or country.
Population pyramids show the bars arranged sideways, rather than upwards. The The line that runs along the bottom of a graph. shows the number of people, the The line that runs up the side of a graph. shows their ages. The bars on the left show the number of males and the bars on the right show the number of females.
A population pyramid for a developed country is usually bullet-shaped like the one below:
population pyramid showing the percentages of the people living in the UK
A population pyramid for a developing country is usually triangle-shaped like the one below:
Population pyramid showing the percentages of the people living in India.
When interpreting a population pyramid, you should include:
- the width of the base of the pyramid: wide or narrow
- the width of the top of the pyramid: wide or narrow
- life expectancy: high or low
- the dependency ratio: the number of active people compared to dependents i.e. under 15s and over 65s
- anomalies – such as bars that are unusually shorter or longer than the overall trend
