US counties by average household size
Oglala Lakota County had the highest average household size of 3135 counties in 2021, at 5.2 persons per household. Kalawao County had the lowest, at 1.2 persons per household. The median was 2.5 persons per household and the figure for the United States was 2.6 persons per household. Source: the U.S. Census Bureau.
Map of counties, 2021
Top 40 counties, 2021
Full ranking
Other periods
About this ranking
Average number of persons per private household. EU countries: EU-SILC. United States: American Community Survey five-year estimate of people in households divided by occupied housing units, where the period shown is the last year of the five-year span.
Covers private households only; people living in institutions or other group quarters are excluded. EU-SILC figures refer to the survey year. The EU and US surveys differ, so their figures are not strictly comparable.
Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. 9 counties with data in other periods have no value for 2021 and are left out rather than filled from another source. Equal values share a rank.
How to cite
U.S. Census Bureau. American Community Survey 5-year estimates, table B25010: average household size of occupied housing units. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat. Retrieved 2026-10-12.Citation styles
APA 7
U.S. Census Bureau. (2026). American Community Survey 5-year estimates, table B25010: average household size of occupied housing units (US counties by average household size, 2021) [Data set]. Retrieved October 12, 2026, from https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat
MLA 9
American Community Survey 5-year estimates, table B25010: average household size of occupied housing units, US counties by average household size, 2021. U.S. Census Bureau, 29 Jan. 2026, https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat. Invokely, https://invokely.ai/rankings/average-household-size/us-counties?period=2021. Accessed 12 Oct. 2026.
Chicago (author-date)
U.S. Census Bureau. 2026. American Community Survey 5-year estimates, table B25010: average household size of occupied housing units. US counties by average household size, 2021. Dataset. Accessed October 12, 2026. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat. Also distributed by Invokely, https://invokely.ai/rankings/average-household-size/us-counties?period=2021.
Harvard
U.S. Census Bureau (2026) American Community Survey 5-year estimates, table B25010: average household size of occupied housing units, US counties by average household size, 2021 [Dataset]. Available at: https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat, via Invokely: https://invokely.ai/rankings/average-household-size/us-counties?period=2021 (Accessed: 12 October 2026).
BibTeX
@misc{census_us_counties_by_average_2021,
author = {{U.S. Census Bureau}},
title = {{American Community Survey 5-year estimates, table B25010: average household size of occupied housing units: US counties by average household size, 2021}},
year = {2026},
howpublished = {Data set},
url = {https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat},
urldate = {2026-10-12},
note = {Accessed via Invokely, https://invokely.ai/rankings/average-household-size/us-counties?period=2021. Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B25010: average household size of occupied housing units. https://www2.census.gov/programs-surveys/acs/summary\_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat. Retrieved 2026-10-12.},
}
RIS
TY - DATA
AU - U.S. Census Bureau
TI - American Community Survey 5-year estimates, table B25010: average household size of occupied housing units: US counties by average household size, 2021
PY - 2026
DA - 2026/01/29
PB - U.S. Census Bureau
DB - Invokely
UR - https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat
L2 - https://invokely.ai/rankings/average-household-size/us-counties?period=2021
Y2 - 2026/10/12
N1 - Accessed via Invokely, https://invokely.ai/rankings/average-household-size/us-counties?period=2021.
N1 - Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B25010: average household size of occupied housing units. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b25010.dat. Retrieved 2026-10-12.
ER -
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Rank US counties by average household size using official data, and cite the source.
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Which county has the highest average household size?
Oglala Lakota County, with 5.2 persons per household in 2021, according to the U.S. Census Bureau.
Which county has the lowest average household size?
Kalawao County, with 1.2 persons per household in 2021.
Where does this ranking come from?
Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, American Community Survey 5-year estimates, table B25010: average household size of occupied housing units. Retrieved 2026-10-12. 9 counties have no value for 2021 and are not ranked.
Average household size: other rankings
- Counties in Michigan
- Counties in Iowa
- Counties in Vermont
- Cities in Nebraska
- Cities in Texas
- Cities in Oregon
US counties: more rankings
- Rent-burdened renter households (rent 30 percent or more of income)
- Fair Market Rent, one bedroom (HUD, monthly)
- County house price annual change, sales and refinances
- Fair Market Rent, four bedrooms (HUD, monthly)
- Population
- Population aged 18 to 64
- Area median family income (HUD)
- Per capita personal income