Janesville Flag

Janesville

County Seat:
No
Area (mi²):
0.061
State:
Illinois

Janesville is a CDP located in Cumberland County, Illinois. Janesville has a 2026 population of 17. Janesville is currently growing at a rate of 6.25% annually and its population has decreased by 0% since the most recent census, which recorded a population of 0 in 2020.

The median age in Janesville is 50.1 years: 45.9 years for males, and 0 years for females. For every 100 females there are 143.8 males.

17
Total Population
277
Density (mi²)
1 6.25%
Growth

Janesville Population

Janesville Population

Data after 2023 is projected based on recent change

Year ↓
Population
Growth
Annual Change
20261716.25%
20251616.67%

Median Age

Overall: 50.1 years
Female: 0 years
Male: 45.9 years

Janesville Adults

There are 39 adults, (0 of whom are seniors) in Janesville.

Sex Ratio

Female: 16 (41%)
Male: 23 (59%)

Demographics

The racial composition of Janesville includes 100% White, and smaller percentages for and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White39100%
Race
Population ↓
Percentage (of total)
White39100%

Janesville Marital Status

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)