Boulder County, Colorado Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 9th-largest in Colorado
The population of Boulder County, Colorado is 328,317 as of the 2023 American Community Survey, making it the 9th-largest county in Colorado. The median household income is $102,772, the median home value is $713,900, and the median age is 37.5.
The population of Boulder County has grown 11.9% since 2010 (295,056 → 330,262), a +0.81% annualized rate.
328,317
Population
+0.81%
Annual growth
452
People / sq mi
$102,772
Median Income
$713,900
Median Home Value
Boulder County covers 726 sq mi of land at 452.0 people per square mile.
About Boulder County, CO
Educational attainment is the headline number in Boulder County: 63.9% of adults 25 and older have a four-year degree. With 328,317 residents, Boulder County is a county in Colorado. That makes it one of the ten largest counties in Colorado in the country, at #9 by population.
Income is a real outlier — the median household pulls in $102,772, putting Boulder County near the top of US counties. Poverty is among the lowest of comparable US counties, at 4.3% — below the national 12.4%. Housing is expensive: the median home is worth $713,900, with typical rent around $1,893.
Boulder County is among the best-educated US counties: 63.9% of adults 25 and older hold a bachelor’s degree, above the national 35.0%. An unusually large 27.9% of workers are remote, above the national 14.0%, and the average commute runs about 23 minutes each way.
The education numbers are the throughline: a college-heavy population in Boulder County usually coincides with higher incomes and a workforce concentrated in professional and information industries.
Boulder County Population History (2010-2024)
The county of Boulder County had a population of 295,056 in 2010 and 330,262 in 2024, a 11.9% growth over 14 years. The peak was 330,953 in 2020. Average annual growth rate: 0.81%.
330,262
Population (2024)
295,056
Population (2010)
330,953
Peak (2020)
0.81%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 295,056 |
| 2011 | 300,045 |
| 2012 | 304,717 |
| 2013 | 309,538 |
| 2014 | 312,525 |
| 2015 | 318,408 |
| 2016 | 321,761 |
| 2017 | 323,019 |
| 2018 | 325,438 |
| 2019 | 326,020 |
| 2020 | 330,953 |
| 2021 | 327,133 |
| 2022 | 328,039 |
| 2023 | 328,419 |
| 2024 | 330,262 |
Race & Ethnicity
| White | 80.7% |
| Black or African American | 0.8% |
| Asian | 0.1% |
| Hispanic or Latino (any race) | 1.5% |
| Two or More Races | 0.0% |
Age & Sex
37.5
Median Age
49.5%
Female
50.5%
Male
15.8%
Age 65+
Age Distribution
Children (under 15): 14.4% · Seniors (65+): 15.8%
Income & Poverty
| Median household income | $102,772+$10,302 vs state |
| Mean household income | $144,869 |
| Per-capita income | $60,272 |
| Poverty rate | 4.3%-1.6% vs state |
| Unemployment rate | 3.1% |
| Employment-to-population | 64.1% |
Top Industries by Employment
The largest employment sector in Boulder County is professional & business services, accounting for 24.3% of workers.
How residents commute
3.1%
Drive alone
3.8%
Carpool
55.6%
Public transit
27.9%
Work from home
23.2 min
Avg commute
Housing
$713,900+$211,700 vs state
Median home value
$1,893
Median rent
62.5%
Homeownership rate
142,809
Total housing units
94.7%
Occupied
5.3%
Vacant
37.5%
Renter-occupied
Social & access
95.6%
With health insurance
97.9%
With broadband internet
55.9%
Foreign-born
4.4%
Veterans (18+)
8.8%
With a disability
85.2%
Speak language other than English at home
Education
95.5%
High School+
63.9%
Bachelor's+
Largest cities in Colorado
Other counties in Colorado
Part of Colorado
Metro areas in Colorado
County rankings
Frequently Asked Questions
Boulder County, Colorado has a population of 328,317 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 9th-largest county in Colorado. Population density is 452 people per square mile.
The population of Boulder County has grown 11.9% since 2010 (295,056 → 330,262), a +0.81% annualized rate.
The median household income in Boulder County, Colorado is $102,772, with mean (average) household income of $144,869 and per-capita income of $60,272. 4.3% of residents live below the federal poverty level.
In Boulder County, the largest racial and ethnic groups are White (80.7%), Hispanic or Latino (1.5%), Black or African American (0.8%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Boulder County, Colorado is 37.5 years. Residents are 49.5% female and 50.5% male.
The median home value in Boulder County is $713,900 and median monthly rent is $1,893. 62.5% of occupied housing units are owner-occupied. The county has 142,809 total housing units, 5.3% of which are vacant.
The largest employment sector in Boulder County, Colorado is professional, scientific, and management services, employing 24.3% of workers. The unemployment rate is 3.1%.
Denver is among the largest cities associated with Boulder County, Colorado, with a population of 713,734.
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Full rankings of Colorado counties
Statewide data for Colorado
Population, race, income, age, and trends across Colorado
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.