Rock County Flag

Rock County

State:
Wisconsin
County Seat:
Janesville

Rock County's estimated 2025 population is 165,152 with a growth rate of 0.27% in the past year according to the most recent United States census data. Rock County is the 9th largest county in Wisconsin. The 2010 population was 160,261 and has seen a growth of 3.05% since that time.

165,152
Total Population
230
Population Density (mi²)
9
Population Rank (State)
437 0.27%
Annual Population Growth

Rock County Population

Rock County Population

Data after 2023 is projected based on recent change

Demographics

The racial composition of Rock County includes 82.35% White, 4.65% Black or African American, 3.37% other race, and smaller percentages for Asian, Native American, Native Hawaiian or Pacific Islander and multiracial populations.

Population by Race

Race
Population
Percentage (of total)
White135,00382.35%
Two or more races13,4248.19%
Black or African American7,6304.65%
Other race5,5213.37%
Asian1,8771.14%
Native American4640.28%
Native Hawaiian or Pacific Islander250.02%

Rock County Marital Status

OverallMalesFemales0%10%20%30%40%50%60%70%80%90%100%

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Rock County's average per capita income is $48,589. Household income levels show a median of $74,390. The poverty rate stands at 9.97%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median
Mean
Married Families$102,632$117,924
Families$88,311$103,922
Households$74,390$89,673
Non Families$44,941$59,884

$48,589

Average Income

$74,390

Median Household Income

9.97%

Poverty Rate