Colorado Population By Age Group and Age Cohort in 2021 (ACS-5Yrs)

Updated on July 8, 2024.

Based on the US Census ACS-5Yrs estimates, in 2021, among the 5.72M Colorado population, the 30-34yrs age group constituted the highest percentage of the total population (7.82%), followed by the 25-29yrs age group (7.73%), and the 35-39yrs age group (7.36%).

In the case of age cohorts, Adults (18-64yrs) constituted the highest percentage of the total population (63.62%), followed by Children (0-17yrs) (22.06%), and Seniors (65yrs and Over) (14.32%).

The first and second charts below shows the percentage of the population by age group and age cohort respectively. The table below also shows the number and percentages for each age group and age cohort.

You can see similar information for other states, and the United States.

Colorado Percentages of Population By Age Group in 2021
30-34yrs
25-29yrs
35-39yrs
40-44yrs
20-24yrs
10-14yrs
15-19yrs
55-59yrs
45-49yrs
50-54yrs
Colorado Percentages of Population By Age Cohort in 2021
Adults (18-64yrs)
Children (0-17yrs)
Seniors (65yrs and Over)
Colorado Population By Age Group in 2021
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Age Group Number of People % of Total
30-34yrs 447489 7.82
25-29yrs 442444 7.73
35-39yrs 421236 7.36
40-44yrs 384013 6.71
20-24yrs 373987 6.54
10-14yrs 370266 6.47
15-19yrs 369984 6.47
55-59yrs 365606 6.39
45-49yrs 364101 6.36
50-54yrs 348095 6.08
5-9yrs 347653 6.07
60-64yrs 344802 6.03
Under 5yrs 324246 5.67
65-69yrs 293687 5.13
70-74yrs 224681 3.93
75-79yrs 129810 2.27
85yrs and Over 88264 1.54
80-84yrs 82812 1.45
Colorado Population By Age Cohort in 2021
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Age Cohort Number of People % of Total
Adults (18-64yrs) 3641187 63.62
Children (0-17yrs) 1262735 22.06
Seniors (65yrs and Over) 819254 14.32