# Counties in Idaho by population aged 18 to 64, 2025

All 44 values come from U.S. Census Bureau for 2025, so the places are comparable.

- Indicator id: `population_18_64_share`
- Unit: %
- Definition: Residents aged 18 to 64 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.
- Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (https://www.census.gov/programs-surveys/popest/data/data-sets.html)
- Retrieved: 2026-10-12
- Citation: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 18 to 64 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/population-18-64/idaho-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Madison County | 71.8 |
| 2 | Latah County | 63.5 |
| 3 | Teton County | 63.1 |
| 4 | Ada County | 61 |
| 5 | Elmore County | 60 |
| 6 | Bannock County | 58.7 |
| 7 | Canyon County | 58.5 |
| 8 | Bonneville County | 56.9 |
| 9 | Twin Falls County | 56.9 |
| 10 | Lincoln County | 56.8 |
| 11 | Nez Perce County | 56.6 |
| 12 | Owyhee County | 56.6 |
| 13 | Blaine County | 56.4 |
| 14 | Jerome County | 56.2 |
| 15 | Gooding County | 56.1 |
| 16 | Fremont County | 56 |
| 17 | Jefferson County | 55.9 |
| 18 | Kootenai County | 55.7 |
| 19 | Bingham County | 55.6 |
| 20 | Power County | 55.5 |
| 21 | Minidoka County | 55.1 |
| 22 | Cassia County | 54.6 |
| 23 | Franklin County | 54.6 |
| 24 | Payette County | 54 |
| 25 | Shoshone County | 53.7 |
| 26 | Boise County | 53.4 |
| 27 | Clearwater County | 53.2 |
| 28 | Gem County | 53 |
| 29 | Caribou County | 53 |
| 30 | Valley County | 52.9 |
| 31 | Washington County | 52.6 |
| 32 | Bonner County | 52.4 |
| 33 | Clark County | 52.2 |
| 34 | Adams County | 51.4 |
| 35 | Benewah County | 51.2 |
| 36 | Camas County | 51.1 |
| 37 | Oneida County | 51 |
| 38 | Butte County | 50.9 |
| 39 | Bear Lake County | 50.9 |
| 40 | Boundary County | 50.6 |
| 41 | Custer County | 50.2 |
| 42 | Lewis County | 50 |
| 43 | Lemhi County | 49.6 |
| 44 | Idaho County | 48 |