Population by age group
According to the 2015 Census, the age group with the highest population in Culasi is 10 to 14, with 4,764 individuals. Conversely, the age group with the lowest population is 80 and over, with 514 individuals.

Combining age groups together, those aged 14 and below, consisting of the the young dependent population which include infants/babies, children and young adolescents/teenagers, make up an aggregate of 33.45% (13,789). Those aged 15 up to 64, roughly, the economically active population and actual or potential members of the work force, constitute a total of 59.68% (24,603). Finally, old dependent population consisting of the senior citizens, those aged 65 and over, total 6.88% (2,836) in all.

The computed Age Dependency Ratios mean that among the population of Culasi, there are 56 youth dependents to every 100 of the working age population; there are 12 aged/senior citizens to every 100 of the working population; and overall, there are 68 dependents (young and old-age) to every 100 of the working population.

The median age of 24 indicates that half of the entire population of Culasi are aged less than 24 and the other half are over the age of 24.

Historical population
The population of Culasi grew from 23,923 in 1960 to 41,228 in 2015, an increase of 17,305 people. The latest census figures in 2015 denote a positive growth rate of 1.02%, or an increase of 2,142 people, from the previous population of 39,086 in 2010.