Yellowstone County, MT population by age group
Sources: U.S. Census Bureau, American Community Survey (ACS) 2021
The largest age group in Yellowstone County, MT was for the group of age 10-14 years with a population of 11,389 (6.96%), according to the 2021 American Community Survey.
At the same time, the smallest age group in Yellowstone County, MT was the 80-84 years with a population of 3,044 (1.86%).
Yellowstone County, MT population by age cohort
To better understand the age distribution of Yellowstone County, MT'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 | 38,563 | 23.57% |
| 18 to 64 years | 97,290 | 59.47% |
| 85 years and over | 27,740 | 16.96% |
Key stats for each age cohort as per our analysis of U.S. Census Bureau American Community Survey:
- Yellowstone County's population under 18 was 23.57%, compared to the 22.51% nationwide.
- Yellowstone County's working population (between 18 and 64) was 59.47%, compared to 61.45% nationwide.
- Yellowstone County's elderly or the senior population (over 65 age) was 16.96% as compared to 16.04% nationwide.
Yellowstone County, MT population pyramid
Population pyramid for Yellowstone County, MT 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 Yellowstone County's population pyramid:
- Youth dependency ratio, which is the number of children aged 0-14 per 100 persons aged 15-64, for Yellowstone County, MT, is 31.1.
- Old-age dependency ratio, which is the number of persons aged 65 or over per 100 persons aged 15-64, for Yellowstone County, MT, is 26.8.
- Total dependency ratio for Yellowstone County, MT is 57.8.
- Potential support ratio, which is the number of youth (working age population) per elderly, for Yellowstone County, MT is 3.7.
Here's the Yellowstone County, MT's male and female population across different age groups:
| Age Group | Population(Male) | Population(Female) | Total Population |
|---|---|---|---|
| Under 5 years | 5,176 | 4,679 | 9,855 |
| 5 to 9 years | 5,310 | 5,657 | 10,967 |
| 10 to 14 years | 6,032 | 5,357 | 11,389 |
| 15 to 19 years | 5,258 | 4,659 | 9,917 |
| 20 to 24 years | 4,602 | 4,865 | 9,467 |
| 25 to 29 years | 5,587 | 5,612 | 11,199 |
| 30 to 34 years | 5,604 | 5,703 | 11,307 |
| 35 to 39 years | 5,234 | 5,445 | 10,679 |
| 40 to 44 years | 5,475 | 5,068 | 10,543 |
| 45 to 49 years | 4,796 | 4,640 | 9,436 |
| 50 to 54 years | 4,815 | 4,717 | 9,532 |
| 55 to 59 years | 5,137 | 5,246 | 10,383 |
| 60 to 64 years | 5,414 | 5,765 | 11,179 |
| 65 to 69 years | 4,540 | 5,085 | 9,625 |
| 70 to 74 years | 3,449 | 3,593 | 7,042 |
| 75 to 79 years | 2,028 | 2,515 | 4,543 |
| 80 to 84 years | 1,332 | 1,712 | 3,044 |
| 85 years and over | 1,263 | 2,223 | 3,486 |