Janesville Population

2010–2026

1,056

2026 projection

2.1% since 2020 (increase)

02004006008001K1.2K201020122014201620182020202220242026

Source: U.S. Census Bureau decennial counts and annual estimates, including 2010–2020 intercensal estimates. 2026 is a projection. Values between recorded years are interpolated.

Use the left and right arrow keys to inspect population observations.

Population by year

Population estimates for Janesville. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
20261,056+40.38%
20251,052-40.38%
20241,056+20.19%
20231,054+30.29%
20221,051+70.67%
20211,044+100.97%
20201,034+30.29%
20191,031+90.88%
20181,022+111.09%
20171,011+80.80%

Showing 10 of 17 years.

The 2020 row compares the April 1 Census count with the July 1, 2019 estimate (about nine months). Its Growth and Annual change therefore do not represent a full year.

Growth since 2020, compared

Janesville is growing about as fast as Bremer County, and slower than Iowa and the U.S.

  • United States+3.1%
  • Iowa+1.5%
  • Janesville+1.3%
  • Bremer County+1.1%

Change from July 1, 2020 to July 1, 2025 population estimates—not annualized growth or site projections.

Source: U.S. Census Bureau. U.S. totals are summed from the 50 states and D.C.; unavailable comparisons are omitted.

Janesville Demographics

47median age

Median age

Female50 yrs
Male44.8 yrs

Adults

723
142 seniors (65+) · 20% of adults581 other adults

Sex

Female 48.6% · 446Male 51.4% · 471

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101

Race and ethnicity

Tap a square or a group below to highlight it.

Each square is about 1% of residents (roughly 9 people).

Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002

Janesville Income

$103,542median household income

Median household income

$103,542

Half of households earn more, half earn less

Median earnings

$58,690

Typical yearly pay for a worker 25 or older.

Poverty rate

5.5%

About 1 in 18 residents

U.S. Census Bureau, 2024 ACS 5-year estimates · Tables S1901, S1501, S1701

Janesville Marital Status

64% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married64%62%67%
Never married26%30%22%
Divorced6%6%6%
Widowed3%2%5%
Separated<1%0%1%

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201