An introduction to population pyramids

1. Changing populations
and places
1. Population Terms & Tools

2. Syllabus link
Population change and demographic
transition over time, including
•natural increase
•fertility rate
•life expectancy
•population structure
•dependency ratios

3. Population terminology

4. Tool 1:
Population Pyramids

5. What are Population
Pyramids?
Population pyramids are a special kind of
graph that show how a country’s population
is structured.
They show the population composition or
structure of a country
Population pyramids are also known as
age-sex pyramids

6. They show two main things:
1.The number or percentage of males and females in
the population;
2.The number or percentage of people in different
age categories.
Males Females
20-25 year old
male age group
55-59 year old
female age group

7. The shape of a population pyramid can tell us a lot
including:
• whether the population is growing, stable or
shrinking.
• information about the history of a country via what
happened to its people;
• They can also tell us about the future of a population

8. Age composition
• The population is normally divided into five year
groups e.g. 0-4, 5-9, 10-14 on the vertical axis.
• Different age groups are known as cohorts
Shown on the vertical axis

9. Sex / Gender Composition
• Figures for males
are recorded on the
left of the diagram.
• Figures for females are
recorded on the right of
the diagram.
Shown on the horizontal axis

10. The horizontal axis may either represent:
• actual numbers • the percentage of the
total population in each
age category.

11. Population pyramids can show:
Change over time

12. Population pyramids can show:

13. Population pyramids can show:
Difference between countries

14. Population pyramids can show:

15. Population pyramids can show:

16. Population pyramids can show:

17. Stage 1 Stage 2
Stage 3 Stage 4 Stage 5
Population Pyramid Shapes

18. 65
15
Age
15
65
Age
Stage 1
•High death and birth rate.
•Each age group rapidly shrinks in size due to high death
rate.
•Short life expectancy.
•Population is not growing.
Stage 2
• High birth rate.
• Rapid fall in death rate.
• Increasing life expectancy.
• Population is rapidly growing.
Stage 3
• Declining birth rate
• Low death rate
• More people living to old age
• Rapidly growing population
Stage 4
•Low birth and death rate
•Longer life expectancy
•An older population that grows slowly if at
all.
Stage 5:
• Low birth rate falls below low death
rate.
• Older population that begins to
shrink in size.
Male MaleFemale Female
There are five different general population population shapes. Each one
corresponds to a different relationship between birth and death rates. It is
expected that most populations will move in a sequence from ‘Stage 1’ to
‘Stage 4’, perhaps even reaching ‘Stage 5’.