In 2022, the population of Allen was 181, a 0.55% decrease year-by-year from 2021. Previously, in 2021, Allen's population was 182, a decline of 1.62% compared to a population of 185 in 2020.
The median age in Allen, KY is 20.3, as per 2021 ACS 5-Year Estimates. Of the total population, 38.97% were under the age of 15, 22.07% aged 15 to 29, 32.86% aged 30 to 64, 6.10% aged 65 to 84, and 0.00% were 85 years of age and older.