Demographics of Jefferson County, Colorado

Jefferson County, Colorado had 580,451 people on July 1, 2025, by the Census Bureau’s estimate: −2,680 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.

Jefferson County, in four figures

580,451
Population: July 1, 2025, Vintage 2025 estimate.; −0.5%
Change since July 2020: −2,680 people.; 40.5 ±0.2
Median age: ACS 2020–⁠2024.; $110,656 ±$1,614
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.

Jefferson County, Colorado's population shrank 0.5% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Jefferson 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

Jefferson County, Colorado's population shrank 0.5% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Jefferson 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	583,131	100.0	100.0
2021	581,002	99.6	100.2
2022	576,703	98.9	100.7
2023	578,084	99.1	101.6
2024	580,359	99.5	102.5
2025	580,451	99.5	103.1

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Population of Jefferson 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	583,131	+202	+162	+11	−99
2021	581,002	−2,129	+137	+225	−2,933
2022	576,703	−4,299	+176	+995	−5,127
2023	578,084	+1,381	+297	+1,916	−785
2024	580,359	+2,275	+479	+3,354	−1,528
2025	580,451	+92	+795	+1,156	−1,904

Age, 2020–2024

The median age is 40.5 ±0.2: for men 39.4 ±0.2 and for women 41.6 ±0.2. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Jefferson County by age, ACS 2020–2024
Age	People	Share	Colorado	United States
Under 5	26,993 ±33	4.7% ±<0.1	5.3% ±<0.1	5.6% ±<0.1
5 to 17	79,977 ±1,285	13.8% ±0.2	15.7% ±0.1	16.3% ±<0.1
18 to 24	43,148 ±1,123	7.4% ±0.2	9.1% ±0.1	9.1% ±<0.1
25 to 44	176,991 ±1,658	30.5% ±0.3	30.3% ±0.1	26.9% ±<0.1
45 to 64	148,625 ±1,586	25.7% ±0.3	23.9% ±0.1	24.8% ±<0.1
65 and over	103,643 ±1,798	17.9% ±0.3	15.6% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $110,656 ±$1,614, and income per person $60,827 ±$743, 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 Jefferson County by income, ACS 2020–2024
Household income	Households	Share	Colorado	United States
Under $25,000	20,020 ±1,098	8.3% ±0.5	11.2% ±0.2	14.6% ±<0.1
$25,000 to $49,999	26,883 ±1,254	11.1% ±0.5	13.6% ±0.2	16.7% ±<0.1
$50,000 to $74,999	31,635 ±1,445	13.1% ±0.6	14.6% ±0.2	15.5% ±<0.1
$75,000 to $99,999	31,080 ±1,191	12.9% ±0.5	12.8% ±0.2	12.6% ±<0.1
$100,000 to $149,999	47,879 ±1,671	19.8% ±0.7	19.2% ±0.2	17.5% ±<0.1
$150,000 to $199,999	33,950 ±1,307	14.0% ±0.5	11.7% ±0.2	9.6% ±<0.1
$200,000 or more	50,288 ±1,621	20.8% ±0.7	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 Jefferson County by age, ACS 2020–2024
Age	Below poverty	Rate	Colorado	United States
All ages	38,163 ±2,218	6.7% ±0.4	9.4% ±0.2	12.5% ±0.1
Under 18	7,432 ±843	7.0% ±0.8	11.1% ±0.3	16.1% ±0.1
18 to 59	20,999 ±1,182	6.4% ±0.4	9.1% ±0.2	11.6% ±0.1
60 and over	9,732 ±672	7.0% ±0.5	8.7% ±0.2	11.0% ±<0.1

Housing, 2020–2024

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Housing in Jefferson County, ACS 2020–2024
Measure	Jefferson County	Colorado	United States
Housing units	253,574 ±276	2,589,053 ±653	143,775,355 ±10,234
Occupied	95.3% ±0.4	91.7% ±0.2	89.9% ±0.1
Vacant	4.7% ±0.4	8.3% ±0.2	10.1% ±0.1
Owner occupied	70.7% ±0.6	66.2% ±0.3	65.2% ±0.3
Renter occupied	29.3% ±0.6	33.8% ±0.3	34.8% ±0.1
Median home value	$637,600 ±$3,257	$539,400 ±$2,069	$332,700 ±$236
Median gross rent	$1,861 ±$19	$1,761 ±$7	$1,413 ±$2
Median year built	1980 ±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 Jefferson County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Colorado	United States
Hispanic or Latino	93,302 ±0	16.1% ±<0.1	22.5% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	435,828 ±890	75.2% ±0.2	64.8% ±0.1	57.4% ±<0.1
Black alone, not Hispanic	6,364 ±596	1.1% ±0.1	3.8% ±0.1	11.9% ±<0.1
Asian alone, not Hispanic	16,591 ±608	2.9% ±0.1	3.2% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	1,285 ±265	0.2% ±<0.1	0.4% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	359 ±104	0.1% ±<0.1	0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	2,248 ±492	0.4% ±0.1	0.5% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	23,400 ±1,281	4.0% ±0.2	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 Jefferson County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Colorado	United States
Born in the state	257,947 ±3,469	44.5% ±0.6	41.2% ±0.2	57.3% ±<0.1
Born in another state	276,647 ±3,035	47.7% ±0.5	47.2% ±0.2	26.9% ±<0.1
Born a citizen outside the states	8,352 ±741	1.4% ±0.1	1.7% ±0.1	1.7% ±<0.1
Born abroad	36,431 ±1,860	6.3% ±0.3	9.8% ±0.1	14.1% ±<0.1
Naturalized citizens	20,648 ±1,084	3.6% ±0.2	4.7% ±0.1	7.4% ±<0.1
Not citizens	15,783 ±1,474	2.7% ±0.3	5.2% ±0.1	6.8% ±<0.1

Jefferson County among the counties of Colorado

4th of 64 by population, July 2025. Every one is listed on the Colorado page.

Counties of Colorado near Jefferson County in population, July 2025
County	July 2025	Change since 2020
El Paso County	757,040	+3.2%
Denver County	740,613	+3.2%
Arapahoe County	673,820	+2.8%
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%

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