Demographics of Rock County, Wisconsin

Rock County, Wisconsin had 166,472 people on July 1, 2025, by the Census Bureau’s estimate: +2,709 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

Rock County, in four figures

166,472
Population: July 1, 2025, Vintage 2025 estimate.; +1.7%
Change since July 2020: +2,709 people.; 40.3 ±0.3
Median age: ACS 2020–⁠2024.; $75,673 ±$2,128
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

Rock County, Wisconsin's population grew 1.7% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Rock County, Wisconsin's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

Rock County, Wisconsin's population grew 1.7% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Rock County, Wisconsin's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	163,763	100.0	100.0
2021	164,150	100.2	100.2
2022	163,954	100.1	100.7
2023	164,619	100.5	101.6
2024	165,665	101.2	102.5
2025	166,472	101.7	103.1

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Population of Rock County, Wisconsin on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	163,763	+79	+49	0	−31
2021	164,150	+387	−58	+33	+261
2022	163,954	−196	−147	+206	−125
2023	164,619	+665	+3	+324	+374
2024	165,665	+1,046	+58	+247	+747
2025	166,472	+807	+72	−33	+764

Age, 2020–2024

The median age is 40.3 ±0.3: for men 39.1 ±0.3 and for women 41.4 ±0.4. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Rock County by age, ACS 2020–2024
Age	People	Share	Wisconsin	United States
Under 5	9,239 ±57	5.6% ±<0.1	5.3% ±<0.1	5.6% ±<0.1
5 to 17	27,564 ±821	16.8% ±0.5	16.0% ±0.1	16.3% ±<0.1
18 to 24	13,812 ±665	8.4% ±0.4	9.3% ±0.1	9.1% ±<0.1
25 to 44	41,027 ±748	25.0% ±0.5	25.2% ±0.1	26.9% ±<0.1
45 to 64	43,440 ±865	26.4% ±0.5	25.6% ±0.1	24.8% ±<0.1
65 and over	29,268 ±1,053	17.8% ±0.6	18.5% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $75,673 ±$2,128, and income per person $38,536 ±$1,081, in 2024 dollars. The median is $77,485 ±$455 in Wisconsin and $80,734 ±$166 in the United States.

Households by income

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Households in Rock County by income, ACS 2020–2024
Household income	Households	Share	Wisconsin	United States
Under $25,000	8,618 ±769	12.8% ±1.1	13.1% ±0.2	14.6% ±<0.1
$25,000 to $49,999	12,539 ±840	18.7% ±1.2	17.9% ±0.2	16.7% ±<0.1
$50,000 to $74,999	12,152 ±941	18.1% ±1.4	17.5% ±0.2	15.5% ±<0.1
$75,000 to $99,999	11,302 ±780	16.8% ±1.2	13.8% ±0.2	12.6% ±<0.1
$100,000 to $149,999	12,036 ±809	17.9% ±1.2	19.1% ±0.2	17.5% ±<0.1
$150,000 to $199,999	6,132 ±482	9.1% ±0.7	9.4% ±0.1	9.6% ±<0.1
$200,000 or more	4,422 ±478	6.6% ±0.7	9.2% ±0.1	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in Rock County by age, ACS 2020–2024
Age	Below poverty	Rate	Wisconsin	United States
All ages	14,980 ±1,167	9.3% ±0.7	10.6% ±0.1	12.5% ±0.1
Under 18	4,667 ±679	12.9% ±1.8	12.8% ±0.3	16.1% ±0.1
18 to 59	6,714 ±615	7.9% ±0.7	10.3% ±0.2	11.6% ±0.1
60 and over	3,599 ±418	8.9% ±1.0	9.3% ±0.2	11.0% ±<0.1

Housing, 2020–2024

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Housing in Rock County, ACS 2020–2024
Measure	Rock County	Wisconsin	United States
Housing units	71,109 ±90	2,778,572 ±1,533	143,775,355 ±10,234
Occupied	94.5% ±0.7	89.2% ±0.2	89.9% ±0.1
Vacant	5.5% ±0.6	10.8% ±0.2	10.1% ±0.1
Owner occupied	71.2% ±1.3	67.8% ±0.3	65.2% ±0.3
Renter occupied	28.8% ±1.2	32.2% ±0.2	34.8% ±0.1
Median home value	$231,600 ±$3,637	$266,500 ±$1,051	$332,700 ±$236
Median gross rent	$1,037 ±$27	$1,087 ±$4	$1,413 ±$2
Median year built	1970 ±2	1975 ±1	1980 ±1

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in Rock County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Wisconsin	United States
Hispanic or Latino	16,646 ±0	10.1% ±<0.1	8.0% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	130,867 ±649	79.6% ±0.4	78.6% ±0.1	57.4% ±<0.1
Black alone, not Hispanic	7,584 ±580	4.6% ±0.4	5.9% ±<0.1	11.9% ±<0.1
Asian alone, not Hispanic	1,779 ±240	1.1% ±0.1	2.9% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	25 to 135	< 0.1% to 0.1%	0.5% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 25	0% to < 0.1%	< 0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	460 ±224	0.3% ±0.1	0.3% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	6,925 ±805	4.2% ±0.5	3.7% ±0.1	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in Rock County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Wisconsin	United States
Born in the state	115,513 ±1,717	70.3% ±1.0	70.3% ±0.1	57.3% ±<0.1
Born in another state	40,569 ±1,775	24.7% ±1.1	23.6% ±0.1	26.9% ±<0.1
Born a citizen outside the states	714 ±223	0.4% ±0.1	0.9% ±<0.1	1.7% ±<0.1
Born abroad	7,554 ±737	4.6% ±0.4	5.2% ±0.1	14.1% ±<0.1
Naturalized citizens	3,151 ±501	1.9% ±0.3	2.5% ±0.1	7.4% ±<0.1
Not citizens	4,403 ±707	2.7% ±0.4	2.7% ±0.1	6.8% ±<0.1

Rock County among the counties of Wisconsin

9th of 72 by population, July 2025. Every one is listed on the Wisconsin page.

Counties of Wisconsin near Rock County in population, July 2025
County	July 2025	Change since 2020
Brown County	275,803	+2.5%
Racine County	198,919	+0.4%
Outagamie County	195,894	+2.6%
Winnebago County	174,218	+1.4%
Kenosha County	168,448	−0.4%
Rock County	166,472	+1.7%
Marathon County	139,432	+1.0%
Washington County	139,238	+1.8%
La Crosse County	121,339	+0.3%
Sheboygan County	118,047	< +0.1%
Eau Claire County	109,033	+3.0%

Elsewhere on the site

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Data retrieved September 25, 2026