City · Iowa
Janesville, Iowa
Janesville, city, mostly in Bremer County (88.9% of its 2020 residents), with a part in Black Hawk County, Iowa. Janesville had 1,052 residents on July 1, 2025 by the Census Bureau's estimate, up 1.3% since 2020; the 2020 Census counted 1,034 and the ACS 2020-2024 5-year estimates put it at 917 (±177). GEOID 1939405.
Residents, July 2025 estimate
1,052
Census Bureau estimate (no margin published)
2020 Census count: 1,034 · ACS 2020-2024: 917 ±177
Median household income
$103,542
±$19,498 (90% margin)
Iowa: $75,059
Median home value
$221,700
±$18,926 (90% margin)
Iowa: $208,000
Median gross rent
$717
±$326 (90% margin)
Iowa: $972
Where is Janesville and what county is it in?
Janesville is a city mostly in Bremer County (88.9% of its 2020 residents), with a part in Black Hawk County, Iowa. It covers 1.4 square miles of land, 744 residents per square mile in 2020.
Janesville is in the Waterloo-Cedar Falls, IA metropolitan statistical area, which takes in 3 counties (Census Bureau delineation, July 2023).
| County | 2020 residents | Share |
|---|---|---|
| Bremer County | 919 | 88.9% |
| Black Hawk County | 115 | 11.1% |
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Janesville, and is it growing?
The Census Bureau estimates that 1,052 people lived in Janesville on July 1, 2025, up 1.3% since 2020, in line with Iowa (+1.5%). The 2020 Census counted 1,034 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 917 (±177).
| Measure | Janesville | Bremer County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 917 ±177 | 25,204 | no clear change |
| Households | 361 ±71 | 9,716 | no clear change |
| Average household size | 2.54 ±0.23 | 2.44 | no clear change |
| Housing units | 429 ±83 | 10,585 | no clear change |
Janesville's population since 2000
From 829 in 2000 to 1,052 in 2025: up 26.9%. The 2000, 2010 and 2020 figures are census counts, each for Janesville as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Janesville?
The median resident of Janesville is 47.0 years old; 21.2% are under 18 and 15.5% are 65 or older. The largest group is non-Hispanic white residents at 97.4%, then non-Hispanic Asian residents at 1.1%.
| Measure | Janesville | Bremer County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 47.0 ±7.4 | 39.0 | +9.3 |
| Under 18 years | 21.2% ±6.4 pts | 22.4% | – |
| 65 years and over | 15.5% ±4.5 pts | 19.8% | – |
| Male | 51.4% ±3.0 pts | 49.8% | – |
| Hispanic or Latino (any race) | 0.4% ±0.7 pts | 2.1% | – |
| White alone, not Hispanic | 97.4% ±2.2 pts | 92.3% | no clear change |
| Black or African American alone, not Hispanic | 0.0% ±2.7 pts | 1.1% | – |
| Asian alone, not Hispanic | 1.1% ±1.7 pts | 0.9% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±2.7 pts | 0.0% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±2.7 pts | 0.0% | – |
| Two or more races, not Hispanic | 0.3% ±0.5 pts | 2.6% | – |
| Some other race alone, not Hispanic | 0.8% ±1.0 pts | 1.0% | – |
| Born outside the United States | 1.5% ±1.8 pts | 1.6% | – |
| Speak a language other than English at home (age 5+) | 1.7% ±1.3 pts | 2.3% | – |
| Civilian veterans (age 18+) | 6.9% ±3.3 pts | 6.3% | – |
| With a disability | 9.3% ±2.9 pts | 11.5% | – |
| No health insurance coverage | 0.4% ±0.8 pts | 2.2% | – |
| High school graduate or higher (age 25+) | 98.7% ±1.2 pts | 96.2% | – |
| Bachelor's degree or higher (age 25+) | 28.9% ±7.4 pts | 36.2% | no clear change |
| Graduate or professional degree (age 25+) | 4.6% ±3.2 pts | 12.1% | – |
| Lived in the same house a year earlier | 96.5% ±3.6 pts | 88.1% | – |
| Moved from another state in the past year | 0.0% ±2.7 pts | 2.2% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Janesville earn?
Half of Janesville's 361 households earn less than $103,542 a year (±$19,498), against $86,784 in Bremer County and $75,059 in Iowa. In 2015-2019 it was $78,457 in 2024 dollars; the margins of error cannot tell the two periods apart.
| Measure | Janesville | Bremer County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $103,542 ±$19,498 | $86,784 | no clear change |
| Mean household income | $103,900 ±$12,959 | $108,261 | – |
| Per capita income | $42,115 ±$6,534 | $43,033 | no clear change |
| People below the poverty line | 5.5% ±3.7 pts | 7.3% | – |
| Children under 18 below the poverty line | 1.5% ±2.5 pts | 8.1% | – |
| Households receiving SNAP | 4.7% ±3.5 pts | 5.3% | – |
| Households with a computer | 98.3% ±2.5 pts | 95.2% | – |
| Households with a broadband subscription | 98.3% ±2.5 pts | 92.6% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Janesville?
Owners occupy 91.4% of Janesville's occupied homes and renters 8.6%. The median owner-occupied home is valued at $221,700 by its owner (±$18,926). The median renter pays $717 a month including utilities.
| Measure | Janesville | Bremer County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $221,700 ±$18,926 | $219,600 | no clear change |
| Median gross rent | $717 ±$326 | $921 | no clear change |
| Renters paying 35% or more of income on rent | 39.3% ±28.0 pts | 25.1% | – |
| Median monthly owner costs, with a mortgage | $1,572 ±$87 | $1,586 | – |
| Owner-occupied homes | 91.4% ±4.4 pts | 79.7% | no clear change |
| Renter-occupied homes | 8.6% ±4.4 pts | 20.3% | – |
| Housing units | 429 ±83 | 10,585 | no clear change |
| Homeowner vacancy rate | 0.0% ±7.3 pts | 0.6% | – |
| Rental vacancy rate | 0.0% ±46.7 pts | 5.6% | – |
| Single-family detached homes | 89.7% ±5.0 pts | 80.9% | – |
| Mobile homes | 2.8% ±2.4 pts | 1.6% | – |
| Built 2020 or later | 0.9% ±1.7 pts | 0.9% | – |
| Built 2010 to 2019 | 10.0% ±3.9 pts | 10.4% | – |
| Built 1939 or earlier | 18.4% ±6.1 pts | 28.2% | – |
| Households with no vehicle | 1.1% ±1.6 pts | 2.6% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How do people in Janesville work and get to work?
79.2% of Janesville's workers drive alone and 8.5% work from home. The average trip to work takes 20.1 minutes.
| Measure | Janesville | Bremer County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 71.4% ±6.7 pts | 66.1% | – |
| Unemployment rate | 2.9% ±2.3 pts | 3.3% | – |
| Drove alone to work | 79.2% ±7.5 pts | 75.0% | – |
| Carpooled | 9.5% ±7.9 pts | 7.1% | – |
| Public transportation | 0.0% ±4.7 pts | 0.0% | – |
| Walked | 2.9% ±3.2 pts | 5.9% | – |
| Worked from home | 8.5% ±4.7 pts | 11.3% | – |
| Mean travel time to work | 20.1 min ±2.3 | 20.1 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Janesville?
No census tract lies mostly in Janesville; 2 tracts reach into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 46Bremer County | 5,245 | $99,554 |
| Tract 26.04Black Hawk County | 4,284 | $81,111 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Janesville) · Census block assignment files
How does Janesville compare with other places in Iowa?
By the Census Bureau's July 2025 estimates, Janesville is the 10,071st-most populous of the 19,476 U.S. incorporated places that have one and the 267th-most populous of 939 in Iowa.
Janesville ranks 35th of 279 places in Iowa with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 267th | 939 |
| Growth 2020-2025 (PEP) | 88th | 275 |
| Residents per square mile | 215th | 279 |
| Median household income | 35th | 279 |
| Per capita income | 75th | 279 |
| Median home value | 70th | 279 |
| Median gross rent | 222nd | 266 |
| Bachelor's degree or higher | 93rd | 279 |
| Median age | 29th | 279 |
| Owner-occupied share | 11th | 279 |
| Work from home | 126th | 221 |
| Travel time to work | 140th | 279 |
Janesville's figures with every place in Iowa (CSV)
Every place in Iowa, sortable · Compare Janesville with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Janesville?
25 of the 57 figures for Janesville on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Janesville are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in Janesville.