Census tract · Rock County
Census Tract 12.01, Rock County, Wisconsin
Census Tract 12.01, GEOID 55105001201, in Rock County, Wisconsin, partly within Janesville, Rock (town), Rock County and Janesville (town). 6,423 residents in the ACS 2020-2024 5-year estimates (±745); the 2020 Census counted 5,709.
Residents, 2020-2024
6,423
±745 (90% margin)
2020 Census count: 5,709
Median household income
$90,597
±$6,107 (90% margin)
Rock County: $75,673
Median home value
$271,300
±$37,359 (90% margin)
Rock County: $231,600
Median gross rent
$1,270
±$531 (90% margin)
Rock County: $1,037
Where is Census Tract 12.01?
Census Tract 12.01 is one of 41 census tracts in Rock County, Wisconsin. It covers 30.20 square miles of land, 189 residents per square mile in 2020. Its GEOID, 55105001201, names it uniquely (how tract numbers and GEOIDs work).
| Place | Share of the tract |
|---|---|
| Janesville | 47% |
| Rock (town), Rock County | 37% |
| Janesville (town) | 15% |
8 census tracts border Census Tract 12.01: Tract 4 ($65,876), Tract 5 ($73,311), Tract 11 ($66,600), Tract 12.02 ($89,012), Tract 14 ($87,091), Tract 22 ($86,750), Tract 27 ($92,391) and Tract 28 ($81,129). The figure in brackets is each tract's median household income.
Whether a tract counts as low- or moderate-income for bank lending (the Community Reinvestment Act) is set by the FFIEC against its metro area's family income: look it up in the FFIEC census geocoder.
Source: 2024 Gazetteer and 2020 block assignment files, U.S. Census Bureau · Census reference files
How many people live in Census Tract 12.01?
The 2020-2024 American Community Survey puts Census Tract 12.01's population at 6,423 (±745) in 2,718 households; the 2020 Census counted 5,709 residents and 2,290 housing units.
| Measure | Tract 12.01 | Rock County |
|---|---|---|
| Total population | 6,423 ±745 | 164,350 |
| Households | 2,718 ±411 | 67,201 |
| Average household size | 2.34 ±0.19 | 2.41 |
| Housing units | 2,743 ±418 | 71,109 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Census Tract 12.01?
The median resident of Census Tract 12.01 is 48.1 years old; 15.6% are under 18 and 21.9% are 65 or older. The largest group is non-Hispanic white residents at 86.8%, then Hispanic or Latino residents (of any race) at 7.5%.
| Measure | Tract 12.01 | Rock County |
|---|---|---|
| Median age | 48.1 ±5.3 | 40.3 |
| Under 18 years | 15.6% ±3.5 pts | 22.4% |
| 65 years and over | 21.9% ±5.3 pts | 17.8% |
| Hispanic or Latino (any race) | 7.5% ±6.3 pts | 10.1% |
| White alone, not Hispanic | 86.8% ±6.8 pts | 79.6% |
| Black or African American alone, not Hispanic | 0.3% ±0.5 pts | 4.6% |
| Asian alone, not Hispanic | 2.1% ±2.6 pts | 1.1% |
| American Indian and Alaska Native alone, not Hispanic | 0.2% ±0.5 pts | 0.0% |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.3 pts | 0.0% |
| Two or more races, not Hispanic | 3.1% ±2.3 pts | 4.2% |
| Some other race alone, not Hispanic | 0.0% ±0.3 pts | 0.3% |
| Born outside the United States | 3.4% ±3.3 pts | 4.6% |
| Speak a language other than English at home (age 5+) | 4.9% ±5.5 pts | 8.8% |
| Civilian veterans (age 18+) | 5.6% ±3.0 pts | 6.9% |
| With a disability | 14.2% ±4.6 pts | 12.8% |
| No health insurance coverage | 5.5% ±5.1 pts | 5.5% |
| High school graduate or higher (age 25+) | 97.1% ±1.6 pts | 92.6% |
| Bachelor's degree or higher (age 25+) | 30.7% ±8.4 pts | 25.8% |
| Graduate or professional degree (age 25+) | 15.0% ±6.6 pts | 8.1% |
| Lived in the same house a year earlier | 91.5% ±4.4 pts | 90.6% |
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 Census Tract 12.01 earn?
Half of the 2,718 households in Census Tract 12.01 earn less than $90,597 a year (±$6,107), against $75,673 across Rock County: 7th highest of the county's 41 tracts with a reliable estimate. 4.5% of residents live below the poverty line.
| Measure | Tract 12.01 | Rock County |
|---|---|---|
| Median household income | $90,597 ±$6,107 | $75,673 |
| Mean household income | $101,218 ±$8,724 | $91,984 |
| Per capita income | $43,903 ±$5,319 | $38,536 |
| People below the poverty line | 4.5% ±2.5 pts | 9.3% |
| Children under 18 below the poverty line | 2.4% ±3.9 pts | 12.9% |
| Households receiving SNAP | 12.7% ±6.3 pts | 12.9% |
| Households with a computer | 97.7% ±2.3 pts | 95.5% |
| Households with a broadband subscription | 92.1% ±6.2 pts | 90.3% |
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 Census Tract 12.01?
Owners occupy 81.9% of Census Tract 12.01's occupied homes and renters 18.1%. The median owner-occupied home is valued at $271,300 by its owner (±$37,359). The median renter pays $1,270 a month including utilities.
| Measure | Tract 12.01 | Rock County |
|---|---|---|
| Median home value (owner-occupied) | $271,300 ±$37,359 | $231,600 |
| Median gross rent | $1,270 ±$531 | $1,037 |
| Renters paying 35% or more of income on rent | 12.6% ±13.6 pts | 35.0% |
| Median monthly owner costs, with a mortgage | $1,725 ±$140 | $1,538 |
| Owner-occupied homes | 81.9% ±9.2 pts | 71.2% |
| Renter-occupied homes | 18.1% ±9.2 pts | 28.8% |
| Housing units | 2,743 ±418 | 71,109 |
| Single-family detached homes | 89.1% ±4.4 pts | 74.4% |
| Mobile homes | 4.8% ±3.6 pts | 2.6% |
| Built 2020 or later | 4.4% ±4.2 pts | 1.2% |
| Built 2010 to 2019 | 2.9% ±2.1 pts | 4.3% |
| Built 1939 or earlier | 9.3% ±4.9 pts | 19.2% |
| Households with no vehicle | 1.3% ±1.5 pts | 6.0% |
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 Census Tract 12.01 get to work?
79.0% of Census Tract 12.01's workers drive alone and 14.0% work from home. The average trip to work takes 24.3 minutes.
| Measure | Tract 12.01 | Rock County |
|---|---|---|
| In the labor force (age 16+) | 63.1% ±6.5 pts | 65.2% |
| Unemployment rate | 4.6% ±4.3 pts | 3.8% |
| Drove alone to work | 79.0% ±7.4 pts | 80.1% |
| Carpooled | 6.2% ±4.0 pts | 7.2% |
| Public transportation | 0.0% ±0.7 pts | 0.5% |
| Walked | 0.4% ±0.8 pts | 1.7% |
| Worked from home | 14.0% ±6.2 pts | 9.2% |
| Mean travel time to work | 24.3 min ±5.1 | 23.8 min |
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
How does Census Tract 12.01 compare with the other tracts in Rock County?
Among Rock County's tracts with a reliable estimate, Census Tract 12.01 ranks as shown below (1 = highest).
| Measure | In Rock County |
|---|---|
| Population | 1st of 41 |
| Residents per square mile | 31st of 41 |
| Median household income | 7th of 41 |
| Per capita income | 11th of 41 |
| Median home value | 11th of 41 |
| Median gross rent | 5th of 41 |
| Poverty rate | 30th of 35 |
| Bachelor's degree or higher | 12th of 39 |
| Median age | 4th of 41 |
| Owner-occupied share | 10th of 41 |
The tracts next to it on Rock County's income ladder
| Tract | Rank | Median household income |
|---|---|---|
| Tract 26.02 | 4th | $92,750±$9,635 · within the margin of this tract |
| Tract 27 | 5th | $92,391±$4,254 · within the margin of this tract |
| Tract 9 | 6th | $91,175±$1,974 · within the margin of this tract |
| Tract 12.01 | 7th | $90,597±$6,107 |
| Tract 12.02 | 8th | $89,012±$4,663 · within the margin of this tract |
| Tract 29.01 | 9th | $87,500±$29,812 · within the margin of this tract |
| Tract 14 | 10th | $87,091±$11,088 · within the margin of this tract |
"Within the margin": the two incomes differ by less than their combined 90% margins, so the survey cannot say which is higher and the ranks between them are not firm.
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · How ranks are computed
How reliable are the figures for Census Tract 12.01?
3 of the 18 figures for Census Tract 12.01 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.
A census tract's figures rest on a few hundred sampled households over five years, so its margins are wider than a city's. Two tracts differ only when the gap between them is larger than their combined 90% margin (the square root of the sum of the two squared margins). 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 · Check it at data.census.gov
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections