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

All 9 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/connecticut-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Greater Bridgeport Planning Region | 61.2 |
| 2 | South Central Connecticut Planning Region | 60.9 |
| 3 | Capitol Planning Region | 60.5 |
| 4 | Southeastern Connecticut Planning Region | 60.4 |
| 5 | Western Connecticut Planning Region | 60.3 |
| 6 | Northeastern Connecticut Planning Region | 59.4 |
| 7 | Naugatuck Valley Planning Region | 59.1 |
| 8 | Lower Connecticut River Valley Planning Region | 58.3 |
| 9 | Northwest Hills Planning Region | 56 |