To find the median age, the ages of all the individuals in the population are arranged in numerical order, and the age that falls in the middle of this list is the median age. For example, if a population consists of 5 people aged 10, 20, 30, 40, and 50, the median age would be 30, because this is the age that falls in the middle of the list.

The median age can be used to provide a snapshot of the age structure of a population, and it can be useful for comparing the age distributions of different populations or for tracking changes in the age structure of a population over time. It is often used in conjunction with other measures of age distribution, such as the mean (average) age and the age-sex pyramid.