Costa Mesa, CA population age distribution
A complete breakdown of Costa Mesa's age demographics from 0 to 85 years, distributed across 18 age groups is listed in the table below.
Age Group | Population | % of Total Population |
---|---|---|
Under 5 years | 6,407 | 5.71% |
5 to 9 years | 5,398 | 4.81% |
10 to 14 years | 6,797 | 6.06% |
15 to 19 years | 6,324 | 5.64% |
20 to 24 years | 6,810 | 6.07% |
25 to 29 years | 11,882 | 10.59% |
30 to 34 years | 10,150 | 9.05% |
35 to 39 years | 8,592 | 7.66% |
40 to 44 years | 8,328 | 7.43% |
45 to 49 years | 7,164 | 6.39% |
50 to 54 years | 7,893 | 7.04% |
55 to 59 years | 7,180 | 6.4% |
60 to 64 years | 5,450 | 4.86% |
65 to 69 years | 4,843 | 4.32% |
70 to 74 years | 3,587 | 3.2% |
75 to 79 years | 2,154 | 1.92% |
80 to 84 years | 1,262 | 1.13% |
85 years and over | 1,927 | 1.72% |
TABLE OF CONTENTS
Costa Mesa, CA population by age group
Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

The largest age group in Costa Mesa, CA was for the group of age 25-29 years with a population of 11,882 (10.59%), according to the 2021 American Community Survey.
At the same time, the smallest age group in Costa Mesa, CA was the 80-84 years with a population of 1,262 (1.13%).
Costa Mesa, CA population by age cohort
To better understand the age distribution of Costa Mesa, CA's population, we divided it into the following 3 cohorts:
- Children : Under the age of 18 years
- Adults (working population): Between the age of 18 and 64 years
- Seniors: 65 years and above

Here's the population for each of the three cohorts.
Age Group | Population | % of Total Population |
---|---|---|
Under 18 years | 22,241 | 19.83% |
18 to 64 years | 76,134 | 67.89% |
85 years and over | 13,773 | 12.28% |
Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:
- Costa Mesa's population under 18 was 19.83%, compared to the 22.51% nationwide.
- Costa Mesa's working population (between 18 and 64) was 67.89%, compared to 61.45% nationwide.
- Costa Mesa's elderly or the senior population (over 65 age) was 12.28% as compared to 16.04% nationwide.
Costa Mesa, CA population pyramid
Population pyramid for Costa Mesa, CA is charted below using the estimates from U.S. Census Bureau's American Community Survey 5-Year estimates. A wide base suggests population increase, narrow base indicates declining birth rates.
Key stats from our analysis of the Costa Mesa's population pyramid:
- Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Costa Mesa, CA, is 23.3.
- Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Costa Mesa, CA, is 17.3.
- Total dependency ratio for Costa Mesa, CA is 40.6.
- Potential support ratio, which is the number of youth (working age population) per elderly, for Costa Mesa, CA is 5.8.

Here's the Costa Mesa, CA's male and female population across different age groups:
Age Group | Population(Male) | Population(Female) | Total Population |
---|---|---|---|
Under 5 years | 3,178 | 3,229 | 6,407 |
5 to 9 years | 2,761 | 2,637 | 5,398 |
10 to 14 years | 3,283 | 3,514 | 6,797 |
15 to 19 years | 3,383 | 2,941 | 6,324 |
20 to 24 years | 3,474 | 3,336 | 6,810 |
25 to 29 years | 6,012 | 5,870 | 11,882 |
30 to 34 years | 5,270 | 4,880 | 10,150 |
35 to 39 years | 4,725 | 3,867 | 8,592 |
40 to 44 years | 4,319 | 4,009 | 8,328 |
45 to 49 years | 4,034 | 3,130 | 7,164 |
50 to 54 years | 4,131 | 3,762 | 7,893 |
55 to 59 years | 3,443 | 3,737 | 7,180 |
60 to 64 years | 2,658 | 2,792 | 5,450 |
65 to 69 years | 2,429 | 2,414 | 4,843 |
70 to 74 years | 1,642 | 1,945 | 3,587 |
75 to 79 years | 1,001 | 1,153 | 2,154 |
80 to 84 years | 516 | 746 | 1,262 |
85 years and over | 683 | 1,244 | 1,927 |
Things to know
What is the population of Costa Mesa, CA under 18?
Costa Mesa's population under the age of 18 is 22,241, as per the latest U.S. Census Bureau's American Community Survey estimates. This population is 19.83% of the total resident population of Costa Mesa, CA.
What is the aging population in Costa Mesa, CA?
Costa Mesa's population aged 65 years and above was 13,773. As per the U.S. Census Bureau's American Community Survey, this population is 12.28% of the entire population.
References
- U.S. Census Bureau American Community Survey (ACS) 2017-2021 5-Year Estimates