In 2016, children ages 0 to 14 years accounted for 16% of the population in Simcoe Muskoka for a total of 86,720 children. In Simcoe County there were a total of 79,100 children and in the District of Muskoka there were a total of 7,620 children. The largest populations of children live in the southern municipalities of Barrie, Bradford West Gwillimbury, Innisfil and New Tecumseth.



Overall, the District of Muskoka had a lower proportion of their population in the 0 to 14 age range (12.6%) compared to Simcoe County (16.5%) in 2016. For both Simcoe and Muskoka, there was a lower percentage of the population in the younger age groups (e.g. 0 to 4 years) compared to the older age groups (10 to 14 years), indicating Simcoe Muskoka has an aging population, and that the population increase from 2011 to 2016 is not a result of new births in the area, but rather relocation into the area over the past five years.

The chart below is a depiction of the child population growth rate from 2015 through to 2041. The population of children less than 1 year of age will increase by 23% from 5,045 in 2015 to 6,202 in 2041. All age groups above 1 year of age will experience similar population growth. The age group with the highest growth rate is 10 to 14 years of age, with an increase of 26% from 29,380 in 2015 to 37,150 in 2041.
By 2041, the population of 0 to 9-year-olds in Simcoe Muskoka is projected to reach more than 67,100, however, the proportion of children is expected to decrease slightly from 11% to 9% of the total population. The further north one travels in Simcoe Muskoka, the smaller the child population.
