Population is composed of the people of different age group. Population composition by age refers to the structure of population of a place or a country by the age. The population of a particular place or country can be divided into different groups to make a demographic study systematic, relevant and scientific. Population composition by age is important for several reasons. The age structure of Nepal’s population has changed significantly over the some years.
Generally, the population of the age group between 15 to 59 years is known as economically active, and the people below these age group (0-14 years and 60 years and above) are considered as economically dependent. However, some people in the economically dependent age group are found to be active in our society.
We know the number of children, economically active adults and elderly people with the help of the classification of people by age group. The study of population composition by age helps to calculate the students’ enrolment ratio. Population can be categorized on the basis of single year, 5 years, 10 years and bigger age group such as 1-14 years, 15-59 years, 60 years and above. It becomes very difficult and lengthy to divide the people in a single age group. Therefore, demographers normally make 5 years age groups rather than making a single age group while studying the population composition by age. It is practically applicable as well.
If we study 5 years-age composition of population according to the census of 2001 AD, we find more population in 0-4, 5-9, 10-14 years age group than other age groups. The population of 5-9 age group shares the highest percentage, i.e. 14.4% of all males and 13.9% of all females. The more the increase of age, the less the population shares in the age group. This can be clearly represented by the giver table.
Table of percentage of distribution of population by age and sex in Nepal, 2001 AD.
| Age group (in years) | Population (%) | |
| Male | Female | |
| 0-4 | 12.3 | 11.9 |
| 5-9 | 14.4 | 13.9 |
| 10-14 | 13.5 | 12.7 |
| 15-19 | 10.4 | 10.6 |
| 20-24 | 8.3 | 9.4 |
| 25-29 | 7.2 | 7.9 |
| 30-34 | 6.4 | 6.7 |
| 35-39 | 5.7 | 5.8 |
| 40-44 | 4.8 | 4.8 |
| 45-49 | 4.1 | 4.0 |
| 50-54 | 3.5 | 3.3 |
| 55-59 | 2.8 | 2.5 |
| 60-64 | 2.3 | 2.3 |
| 65-69 | 1.7 | 1.7 |
| 70-74 | 1.2 | 1.2 |
| 75+ | 1.3 | 1.3 |
(Source: CBS, 2001 AD)
The table clearly shows that the percentage of male and female is decreasing along with the higher age group.
Population composition can be broad age group in Nepal, 2001
| Age group | 2001 AD | |
| population | % | |
| 0-14 | 8948587 | 39.35 |
| 15-59 | 12310968 | 54.15 |
| 60+ | 1477379 | 6.50 |
| Total | 2,27,36,934 | 100 |
(Source: CBS, 2001)