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 x-axis shows the number of people, the y-axis 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