The total population of St. Charles is estimated to be 123 with 87 males (70.73%) and 36 females (29.27%). There are 51 less females than males in St. Charles.
In 2022, the population of St. Charles was 180, a 4.65% increase year-by-year from 2021. Previously, in 2021, St. Charles's population was 172, an increase of 6.17% compared to a population of 162 in 2020.
The median age in St. Charles, ID is 58.1, as per 2021 ACS 5-Year Estimates. Of the total population, 5.98% were under the age of 15, 27.35% aged 15 to 29, 27.35% aged 30 to 64, 39.32% aged 65 to 84, and 0.00% were 85 years of age and older.