Demographics of Buchanan County, Iowa

Buchanan County, Iowa had 20,883 people on July 1, 2025, by the Census Bureau’s estimate: +275 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.

Buchanan County, in four figures

20,883
Population: July 1, 2025, Vintage 2025 estimate.; +1.3%
Change since July 2020: +275 people.; 40.3 ±0.4
Median age: ACS 2020–⁠2024.; $78,236 ±$3,797
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.

Buchanan County, Iowa's population grew 1.3% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Buchanan County, Iowa'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

Buchanan County, Iowa's population grew 1.3% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Buchanan County, Iowa'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	20,608	100.0	100.0
2021	20,718	100.5	100.2
2022	20,705	100.5	100.7
2023	20,725	100.6	101.6
2024	20,711	100.5	102.5
2025	20,883	101.3	103.1

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Population of Buchanan County, Iowa on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	20,608	+46	+23	0	+17
2021	20,718	+110	+44	+14	+37
2022	20,705	−13	+20	+29	−58
2023	20,725	+20	+39	+40	−54
2024	20,711	−14	+55	+22	−91
2025	20,883	+172	+42	+16	+116

Age, 2020–2024

The median age is 40.3 ±0.4: for men 39.0 ±0.7 and for women 41.5 ±1.0. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Buchanan County by age, ACS 2020–2024
Age	People	Share	Iowa	United States
Under 5	1,334 ±32	6.4% ±0.2	5.9% ±<0.1	5.6% ±<0.1
5 to 17	3,917 ±221	18.9% ±1.1	17.0% ±0.1	16.3% ±<0.1
18 to 24	1,497 ±164	7.2% ±0.8	10.0% ±0.1	9.1% ±<0.1
25 to 44	4,846 ±218	23.4% ±1.1	25.1% ±0.1	26.9% ±<0.1
45 to 64	5,245 ±225	25.3% ±1.1	23.9% ±0.1	24.8% ±<0.1
65 and over	3,855 ±247	18.6% ±1.2	18.1% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $78,236 ±$3,797, and income per person $36,527 ±$1,505, in 2024 dollars. The median is $75,059 ±$418 in Iowa and $80,734 ±$166 in the United States.

Households by income

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Households in Buchanan County by income, ACS 2020–2024
Household income	Households	Share	Iowa	United States
Under $25,000	1,072 ±171	13.0% ±2.0	13.9% ±0.2	14.6% ±<0.1
$25,000 to $49,999	1,467 ±192	17.8% ±2.3	18.5% ±0.3	16.7% ±<0.1
$50,000 to $74,999	1,439 ±185	17.4% ±2.2	17.5% ±0.3	15.5% ±<0.1
$75,000 to $99,999	1,366 ±184	16.6% ±2.2	14.0% ±0.3	12.6% ±<0.1
$100,000 to $149,999	1,749 ±207	21.2% ±2.5	18.7% ±0.3	17.5% ±<0.1
$150,000 to $199,999	731 ±140	8.9% ±1.7	8.8% ±0.2	9.6% ±<0.1
$200,000 or more	428 ±93	5.2% ±1.1	8.6% ±0.2	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 Buchanan County by age, ACS 2020–2024
Age	Below poverty	Rate	Iowa	United States
All ages	1,766 ±359	8.6% ±1.7	11.1% ±0.2	12.5% ±0.1
Under 18	457 ±135	8.7% ±2.5	12.9% ±0.3	16.1% ±0.1
18 to 59	878 ±201	8.7% ±2.0	11.4% ±0.3	11.6% ±0.1
60 and over	431 ±93	8.2% ±1.7	8.8% ±0.2	11.0% ±<0.1

Housing, 2020–2024

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Housing in Buchanan County, ACS 2020–2024
Measure	Buchanan County	Iowa	United States
Housing units	8,945 ±31	1,437,699 ±523	143,775,355 ±10,234
Occupied	92.3% ±2.2	91.5% ±0.3	89.9% ±0.1
Vacant	7.7% ±2.2	8.5% ±0.3	10.1% ±0.1
Owner occupied	82.1% ±2.0	71.7% ±0.3	65.2% ±0.3
Renter occupied	17.9% ±2.0	28.3% ±0.3	34.8% ±0.1
Median home value	$176,000 ±$8,421	$208,000 ±$1,141	$332,700 ±$236
Median gross rent	$848 ±$68	$972 ±$6	$1,413 ±$2
Median year built	1973 ±2	1972 ±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 Buchanan County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Iowa	United States
Hispanic or Latino	400 ±0	1.9% ±<0.1	7.3% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	19,649 ±54	95.0% ±0.3	82.3% ±0.1	57.4% ±<0.1
Black alone, not Hispanic	39 to 209	0.2% to 1.0%	3.8% ±0.1	11.9% ±<0.1
Asian alone, not Hispanic	16 to 64	0.1% to 0.3%	2.5% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	3 to 31	< 0.1% to 0.1%	0.2% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 26	0% to 0.1%	0.2% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	0 to 19	0% to 0.1%	0.3% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	451 ±102	2.2% ±0.5	3.5% ±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 Buchanan County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Iowa	United States
Born in the state	17,918 ±380	86.6% ±1.8	69.6% ±0.2	57.3% ±<0.1
Born in another state	2,480 ±379	12.0% ±1.8	23.8% ±0.2	26.9% ±<0.1
Born a citizen outside the states	15 to 55	0.1% to 0.3%	0.7% ±<0.1	1.7% ±<0.1
Born abroad	261 ±120	1.3% ±0.6	5.9% ±0.1	14.1% ±<0.1
Naturalized citizens	20 to 130	0.1% to 0.6%	2.6% ±0.1	7.4% ±<0.1
Not citizens	77 to 295	0.4% to 1.4%	3.3% ±0.1	6.8% ±<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%.

Buchanan County among the counties of Iowa

30th of 99 by population, July 2025. Every one is listed on the Iowa page.

Counties of Iowa near Buchanan County in population, July 2025
County	July 2025	Change since 2020
Plymouth County	25,697	0%
Bremer County	25,296	+1.1%
Washington County	22,667	+0.6%
Mahaska County	21,880	−1.2%
Jones County	21,253	+2.9%
Buchanan County	20,883	+1.3%
Buena Vista County	20,449	−1.7%
Carroll County	20,303	−2.0%
Winneshiek County	19,733	−1.6%
Henry County	19,349	−5.4%
Jackson County	19,288	−0.8%

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