County · Colorado

Boulder County, Colorado

Boulder County, Colorado. Boulder County had 328,560 residents in 2025 by the Census Bureau's estimate, down 0.7% since 2020, while Colorado grew 4.1%. It holds 34 places (10 cities, villages and boroughs and 24 census-designated) and 78 census tracts. GEOID 08013.

Boulder County is the county of the Boulder, CO metropolitan statistical area (the Census Bureau's July 2023 delineation).

Residents, July 2025 estimate

328,560

Census Bureau estimate (no margin published)
2020 Census count: 330,758 · ACS 2020-2024: 328,961

Median household income

$103,994

±$2,268 (90% margin)
Colorado: $95,470

Median home value

$756,300

±$14,324 (90% margin)
Colorado: $539,400

Median gross rent

$1,966

±$30 (90% margin)
Colorado: $1,761

How many people live in Boulder County, and is it growing?

The 2020 Census counted 330,758 residents in Boulder County. The Census Bureau estimates 328,560 for July 1, 2025, down 0.7% since 2020, while Colorado grew 4.1%. The 2020-2024 American Community Survey puts the population at 328,961 over 726 square miles of land.

July 2020→2021 −3,657 (327,325)
2021→2022 +589 (327,914)
2022→2023 +31 (327,945)
2023→2024 +1,540 (329,485)
2024→2025 −925 (328,560)

Boulder County in Colorado. Boundaries: Census Bureau 2024.

Counts, ACS 2020-2024 5-year estimates, with the change from 2015-2019
Measure	Boulder County	Colorado	Change since 2015-2019
Total population	328,961	5,862,189	+6,451
Households	137,008±795	2,374,218	+9,593
Average household size	2.30±0.01	2.42	−0.14
Housing units	144,729±121	2,589,053	+8,633

Boulder County's population since 2000

From 291,288 in 2000 to 328,560 in 2025: up 12.8%. The 2000, 2010 and 2020 figures are census counts. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.

2000 Census 291,288
2005 (estimate) 280,241
2010 Census 294,567
2015 (estimate) 318,408
2020 Census 330,758
2025 (estimate) 328,560

Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); PEP Vintage 2025 (CO-EST2025); 2020 Census · Check it at data.census.gov

What cities and towns are in Boulder County?

Boulder County holds 34 places: 10 cities, villages and boroughs (incorporated places) and 24 census-designated places. The largest is Boulder with 105,689 residents (2025 estimate). Places that cross a county line are listed with the share of their 2020 residents who live in this county.

Places in Boulder County, ACS 2020-2024 5-year estimates. Ring: estimate with a coefficient of variation over 40%.

Boulder	city	108,250	106,433±77	$87,493	$1,039,500	21.5%	100%
Longmont	city	98,885	99,406±405	$90,671	$572,800	8.6%	99%
Lafayette	city	30,411	30,602±233	$119,040	$686,500	5.6%	100%
Louisville	city	21,226	20,786±32	$147,319	$883,900	4.5%	100%
Superior	town	13,094	13,305±67	$159,434	$903,900	3.2%	100%
Erie	town	30,038	33,808±31	$173,349	$736,500	2.3%	42%
Gunbarrel	CDP	9,554	10,051±911	$109,407	$821,000	8.8%	100%
Niwot	CDP	4,306	3,447±524	$146,492	$995,700	2.2%	100%
Lyons	town	2,209	1,838±385	$122,837	$845,400	11.9%	100%
Nederland	town	1,471	1,655±302	$122,917	$707,100	2.7%	100%
Paragon EstatesGEOID 0857445	CDP	975	667±228	$230,268	$1,617,500	4.9%	100%
Pine Brook HillGEOID 0859240	CDP	975	543±253	$63,606	$1,099,100	3.1%	100%
Lazy AcresGEOID 0844270	CDP	957	778±310	$147,625	$1,024,700	17.1%	100%
Coal Creek, Boulder County	CDP	2,494	2,346±516	$134,250	$625,800	5.4%	27%
Allenspark	CDP	568	825±268	$108,056	$742,900	8.2%	100%
Eldorado SpringsGEOID 0823630	CDP	559	320±125	$133,008	$809,200	9.1%	100%
AltonaGEOID 0801740	CDP	512	587±229	$149,327	$1,084,000	3.9%	100%
St. Ann HighlandsGEOID 0867040	CDP	325	453±256	$188,125	$936,200	0.0%	100%
SugarloafGEOID 0874980	CDP	274	474±267	not published	$1,255,400	0.0%	100%
JamestownGEOID 0839195	town	256	324±115	$149,375	$595,900	2.5%	100%
Mountain MeadowsGEOID 0852210	CDP	237	180±74	not published	$1,038,800	0.0%	100%
Gold HillGEOID 0830945	CDP	218	178±66	not published	$611,900	29.2%	100%
Bark RanchGEOID 0804620	CDP	202	199±62	$115,521	$772,100	0.0%	100%
SunshineGEOID 0875585	CDP	198	330±221	not published	$1,043,600	7.3%	100%
Tall TimberGEOID 0876325	CDP	185	382±283	$203,110	$1,086,200	0.0%	100%
CrismanGEOID 0818585	CDP	179	268±143	$172,574	$846,600	6.7%	100%
EldoraGEOID 0823575	CDP	140	465±355	not published	$500,000	52.9%	100%
Seven HillsGEOID 0869110	CDP	129	183±144	not published	not published	0.0%	100%
WardGEOID 0882735	town	128	103±50	$56,875	$322,200	22.3%	100%
Bonanza Mountain EstatesGEOID 0807580	CDP	127	56±54	not published	not published	7.1%	100%
Glendale, Boulder CountyGEOID 0830350	CDP	64	69±55	$199,063	$823,500	0.0%	100%
ValmontGEOID 0880370	CDP	64	27±19	$75,357	$692,300	11.1%	100%
LeynerGEOID 0844695	CDP	40	0±14	not published	not published	–	100%
Hidden LakeGEOID 0835860	CDP	24	29±45	not published	not published	0.0%	100%

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 place-by-county parts · Check it at data.census.gov

Who lives in Boulder County?

The median resident of Boulder County is 37.7 years old; 17.5% are under 18 and 16.4% are 65 or older. The largest group is non-Hispanic white residents at 74.5%, then Hispanic or Latino residents (of any race) at 14.7%. 10.1% of residents were born outside the United States.

Age, origin and education, ACS 2020-2024 5-year estimates. Race groups are non-Hispanic; Hispanic includes any race.
Measure	Boulder County	Colorado	Change since 2015-2019
Median age	37.7±0.2	37.7	+1.1
Under 18 years	17.5%	21.0%	–
65 years and over	16.4%±0.1 pts	15.6%	–
Hispanic or Latino (any race)	14.7%	22.5%	+0.8 pts
White alone, not Hispanic	74.5%±0.2 pts	64.8%	−3.1 pts
Black or African American alone, not Hispanic	0.8%±0.1 pts	3.8%	no clear change
Asian alone, not Hispanic	4.7%±0.2 pts	3.2%	no clear change
American Indian and Alaska Native alone, not Hispanic	0.2%±0.1 pts	0.4%	–
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0.1%±0.1 pts	0.1%	–
Two or more races, not Hispanic	4.8%±0.3 pts	4.6%	–
Some other race alone, not Hispanic	0.3%±0.1 pts	0.5%	–
Born outside the United States	10.1%±0.4 pts	9.8%	−0.6 pts
Speak a language other than English at home (age 5+)	15.1%±0.6 pts	16.2%	–
Civilian veterans (age 18+)	4.3%±0.3 pts	7.5%	–
With a disability	9.4%±0.4 pts	11.4%	–
No health insurance coverage	4.4%±0.4 pts	7.7%	no clear change
High school graduate or higher (age 25+)	95.8%±0.4 pts	92.9%	–
Bachelor's degree or higher (age 25+)	64.2%±0.8 pts	45.7%	+2.1 pts
Graduate or professional degree (age 25+)	30.0%±0.7 pts	17.6%	–
Moved from another state in the past year	5.1%±0.4 pts	3.8%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov

What do households in Boulder County earn?

Half of Boulder County's 137,008 households earn less than $103,994 a year (±$2,268), against $95,470 in Colorado. In 2015-2019 it was $102,171 in 2024 dollars; the margins of error cannot tell the two periods apart. 11.2% of residents live below the poverty line.

Income and poverty in 2024 dollars, ACS 2020-2024 5-year estimates
Measure	Boulder County	Colorado	Change since 2015-2019
Median household income	$103,994±$2,268	$95,470	no clear change
Mean household income	$148,847±$3,975	$128,255	–
Per capita income	$62,436±$1,617	$52,636	+$4,808
People below the poverty line	11.2%±0.6 pts	9.4%	no clear change
Children under 18 below the poverty line	7.0%±1.3 pts	11.1%	no clear change
Households receiving SNAP	5.9%±0.5 pts	8.5%	–
Households with a broadband subscription	95.7%±0.4 pts	93.5%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What does housing cost in Boulder County?

Owners occupy 62.0% of Boulder County's occupied homes and renters 38.0%. The median owner-occupied home is valued at $756,300 by its owner (±$14,324). The median renter pays $1,966 a month including utilities, and 50.0% of renters pay 35% or more of their income on rent.

Housing, ACS 2020-2024 5-year estimates
Measure	Boulder County	Colorado	Change since 2015-2019
Median home value (owner-occupied)	$756,300±$14,324	$539,400	+$144,276
Median gross rent	$1,966±$30	$1,761	+$126
Renters paying 35% or more of income on rent	50.0%±1.8 pts	42.7%	no clear change
Median monthly owner costs, with a mortgage	$2,743±$54	$2,326	–
Owner-occupied homes	62.0%±0.9 pts	66.2%	no clear change
Housing units	144,729±121	2,589,053	+8,633
Homeowner vacancy rate	0.9%±0.3 pts	0.8%	–
Rental vacancy rate	4.0%±0.8 pts	5.1%	–
Single-family detached homes	57.2%±0.8 pts	61.4%	–
Mobile homes	2.3%±0.4 pts	3.5%	–
Built 2020 or later	2.0%±0.3 pts	3.0%	–
Built 1939 or earlier	5.9%±0.5 pts	7.0%	–

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov

How many new homes is Boulder County building?

Builders took permits for 2,001 new housing units across Boulder County in 2025 (428 single-family), 6.1 per 1,000 residents.

2019 1,650 units
2020 1,634 units
2021 1,237 units
2022 1,642 units
2023 1,642 units
2024 1,680 units
2025 2,001 units

Source: Building Permits Survey, annual county files 2019-2025, U.S. Census Bureau · Census Building Permits Survey

How do people in Boulder County get to work?

52.8% of Boulder County's workers drive alone and 31.2% work from home. The average trip to work takes 22.3 minutes. The unemployment rate in 2020-2024 averaged 4.8%.

Work and commuting, ACS 2020-2024 5-year estimates
Measure	Boulder County	Colorado	Change since 2015-2019
In the labor force (age 16+)	66.9%±0.7 pts	68.6%	–
Unemployment rate	4.8%±0.4 pts	4.6%	+0.6 pts
Drove alone to work	52.8%±1.1 pts	65.1%	–
Carpooled	5.3%±0.5 pts	7.7%	–
Public transportation	2.6%±0.4 pts	1.6%	–
Walked	4.0%±0.4 pts	2.5%	–
Worked from home	31.2%±1.1 pts	21.0%	+18.4 pts
Mean travel time to work	22.3 min±0.5	25.2 min	−1.1 min

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov

What are Boulder County's census tracts?

Boulder County is divided into 78 census tracts. Among those with a reliable estimate, median household income runs from $23,590 (Tract 126.10) to $244,179 (Tract 121.01).

All 78 census tracts of Boulder County, with their figures

Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Check it at data.census.gov

How does Boulder County compare with Colorado's other counties?

Boulder County's rank among Colorado's counties with a reliable estimate (1 = highest)
Measure	Rank
Population	9th of 64
Growth 2020-2025	44th of 64
Residents per square mile	5th of 64
Median household income	8th of 64
Median home value	5th of 64
Median gross rent	6th of 63
Poverty rate	30th of 63
Bachelor's degree or higher	3rd of 64
Median age	51st of 64

Every county in Colorado

Source: PlainCities ranks from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections

Not on this page: crime, weather and schools for Boulder County are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.