Demographics of Boulder County, Colorado

Boulder County, Colorado had 328,560 people on July 1, 2025, by the Census Bureau’s estimate: −2,422 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.

Boulder County, in four figures

328,560
Population: July 1, 2025, Vintage 2025 estimate.; −0.7%
Change since July 2020: −2,422 people.; 37.7 ±0.2
Median age: ACS 2020–⁠2024.; $103,994 ±$2,268
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.

Boulder County, Colorado's population shrank 0.7% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Boulder County, Colorado'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

Boulder County, Colorado's population shrank 0.7% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Boulder County, Colorado'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	330,982	100.0	100.0
2021	327,325	98.9	100.2
2022	327,914	99.1	100.7
2023	327,945	99.1	101.6
2024	329,485	99.5	102.5
2025	328,560	99.3	103.1

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Population of Boulder County, Colorado on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	330,982	+221	+71	+23	−2
2021	327,325	−3,657	+373	+334	−4,247
2022	327,914	+589	+261	+1,225	−624
2023	327,945	+31	+248	+1,789	−1,976
2024	329,485	+1,540	+182	+2,415	−1,053
2025	328,560	−925	+244	+1,064	−2,248

Age, 2020–2024

The median age is 37.7 ±0.2: for men 36.6 ±0.2 and for women 39.0 ±0.3. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Boulder County by age, ACS 2020–2024
Age	People	Share	Colorado	United States
Under 5	12,786 ±58	3.9% ±<0.1	5.3% ±<0.1	5.6% ±<0.1
5 to 17	44,929 ±1,034	13.7% ±0.3	15.7% ±0.1	16.3% ±<0.1
18 to 24	50,617 ±1,708	15.4% ±0.5	9.1% ±0.1	9.1% ±<0.1
25 to 44	86,201 ±1,060	26.2% ±0.3	30.3% ±0.1	26.9% ±<0.1
45 to 64	80,486 ±1,223	24.5% ±0.4	23.9% ±0.1	24.8% ±<0.1
65 and over	53,942 ±1,414	16.4% ±0.4	15.6% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $103,994 ±$2,268, and income per person $62,436 ±$1,617, in 2024 dollars. The median is $95,470 ±$578 in Colorado and $80,734 ±$166 in the United States.

Households by income

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Households in Boulder County by income, ACS 2020–2024
Household income	Households	Share	Colorado	United States
Under $25,000	17,193 ±1,212	12.5% ±0.9	11.2% ±0.2	14.6% ±<0.1
$25,000 to $49,999	16,641 ±1,037	12.1% ±0.8	13.6% ±0.2	16.7% ±<0.1
$50,000 to $74,999	17,367 ±912	12.7% ±0.7	14.6% ±0.2	15.5% ±<0.1
$75,000 to $99,999	14,906 ±1,057	10.9% ±0.8	12.8% ±0.2	12.6% ±<0.1
$100,000 to $149,999	23,243 ±1,103	17.0% ±0.8	19.2% ±0.2	17.5% ±<0.1
$150,000 to $199,999	15,138 ±924	11.0% ±0.7	11.7% ±0.2	9.6% ±<0.1
$200,000 or more	32,520 ±1,178	23.7% ±0.8	17.0% ±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 Boulder County by age, ACS 2020–2024
Age	Below poverty	Rate	Colorado	United States
All ages	35,257 ±1,914	11.2% ±0.6	9.4% ±0.2	12.5% ±0.1
Under 18	3,974 ±671	7.0% ±1.2	11.1% ±0.3	16.1% ±0.1
18 to 59	26,188 ±1,513	14.0% ±0.8	9.1% ±0.2	11.6% ±0.1
60 and over	5,095 ±517	7.1% ±0.7	8.7% ±0.2	11.0% ±<0.1

Housing, 2020–2024

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Housing in Boulder County, ACS 2020–2024
Measure	Boulder County	Colorado	United States
Housing units	144,729 ±121	2,589,053 ±653	143,775,355 ±10,234
Occupied	94.7% ±0.5	91.7% ±0.2	89.9% ±0.1
Vacant	5.3% ±0.5	8.3% ±0.2	10.1% ±0.1
Owner occupied	62.0% ±0.8	66.2% ±0.3	65.2% ±0.3
Renter occupied	38.0% ±1.0	33.8% ±0.3	34.8% ±0.1
Median home value	$756,300 ±$14,324	$539,400 ±$2,069	$332,700 ±$236
Median gross rent	$1,966 ±$30	$1,761 ±$7	$1,413 ±$2
Median year built	1986 ±1	1988 ±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 Boulder County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Colorado	United States
Hispanic or Latino	48,466 ±0	14.7% ±<0.1	22.5% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	245,197 ±710	74.5% ±0.2	64.8% ±0.1	57.4% ±<0.1
Black alone, not Hispanic	2,490 ±349	0.8% ±0.1	3.8% ±0.1	11.9% ±<0.1
Asian alone, not Hispanic	15,302 ±631	4.7% ±0.2	3.2% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	547 ±141	0.2% ±<0.1	0.4% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	204 ±87	0.1% ±<0.1	0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	1,053 ±260	0.3% ±0.1	0.5% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	15,702 ±995	4.8% ±0.3	4.6% ±0.1	4.3% ±<0.1

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 Boulder County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Colorado	United States
Born in the state	108,460 ±2,379	33.0% ±0.7	41.2% ±0.2	57.3% ±<0.1
Born in another state	181,804 ±2,618	55.3% ±0.8	47.2% ±0.2	26.9% ±<0.1
Born a citizen outside the states	5,438 ±585	1.7% ±0.2	1.7% ±0.1	1.7% ±<0.1
Born abroad	33,259 ±1,463	10.1% ±0.4	9.8% ±0.1	14.1% ±<0.1
Naturalized citizens	17,340 ±1,102	5.3% ±0.3	4.7% ±0.1	7.4% ±<0.1
Not citizens	15,919 ±1,052	4.8% ±0.3	5.2% ±0.1	6.8% ±<0.1

Boulder County among the counties of Colorado

9th of 64 by population, July 2025. Every one is listed on the Colorado page.

Counties of Colorado near Boulder County in population, July 2025
County	July 2025	Change since 2020
Jefferson County	580,451	−0.5%
Adams County	554,668	+6.6%
Douglas County	399,396	+10.8%
Weld County	378,426	+14.2%
Larimer County	377,292	+4.8%
Boulder County	328,560	−0.7%
Pueblo County	169,277	+0.6%
Mesa County	162,845	+4.4%
Broomfield County	79,174	+6.3%
Garfield County	63,474	+2.7%
La Plata County	56,898	+2.2%

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