Boulder Population

1870–2026

105.22K

2026 projection

2.8% since 2020 (decrease)

020K40K60K80K100K120K18801900192019401960198020002020

Source: U.S. Census Bureau decennial counts and annual estimates, including 2010–2020 intercensal estimates. 2026 is a projection. Values between recorded years are interpolated.

Use the left and right arrow keys to inspect population observations.

Population by year

Population estimates for Boulder. Annual change is shown as a percentage. Growth is the total change since the preceding observation.
2026105,220-4690.44%
2025105,689-8680.81%
2024106,557+920.09%
2023106,465+4270.40%
2022106,038+1,6301.56%
2021104,408-3,8423.55%
2020108,250+1380.13%
2019108,112-1,3211.21%
2018109,433-50.00%
2017109,438+1,0030.92%

Showing 10 of 31 years.

The 2020 row compares the April 1 Census count with the July 1, 2019 estimate (about nine months). Its Growth and Annual change therefore do not represent a full year.

Growth since 2020, compared

Boulder has a population change lower than Boulder County, Colorado, and the U.S.

  • Colorado+3.9%
  • United States+3.1%
  • Boulder County−0.7%
  • Boulder−2.5%

Change from July 1, 2020 to July 1, 2025 population estimates—not annualized growth or site projections.

Source: U.S. Census Bureau. U.S. totals are summed from the 50 states and D.C.; unavailable comparisons are omitted.

Boulder Demographics

28.8median age

Median age

Female29.4 yrs
Male28.3 yrs

Adults

93,927
13,474 seniors (65+) · 14% of adults80,453 other adults

Sex

Female 48.3% · 51,459Male 51.7% · 54,974

Population by age

MaleFemale85+ years, male: 87785+ years, female: 1,19680–84 years, male: 57980–84 years, female: 77075–79 years, male: 1,13675–79 years, female: 1,31570–74 years, male: 1,60370–74 years, female: 2,03965–69 years, male: 1,96065–69 years, female: 1,99960–64 years, male: 2,14360–64 years, female: 1,99155–59 years, male: 2,41855–59 years, female: 2,35850–54 years, male: 2,78650–54 years, female: 2,53445–49 years, male: 2,43545–49 years, female: 2,67540–44 years, male: 2,77540–44 years, female: 2,71935–39 years, male: 3,17435–39 years, female: 2,41130–34 years, male: 3,82830–34 years, female: 3,10125–29 years, male: 5,49825–29 years, female: 4,30420–24 years, male: 11,70720–24 years, female: 9,88315–19 years, male: 6,84915–19 years, female: 7,60710–14 years, male: 1,78810–14 years, female: 2,1595–9 years, male: 2,0165–9 years, female: 1,3850–4 years, male: 1,4020–4 years, female: 1,01385+80–8475–7970–7465–6960–6455–5950–5445–4940–4435–3930–3425–2920–2415–1910–145–90–45K5K10K10K

Hover or tap an age group to see exact counts. Use the up and down arrow keys to inspect age groups.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S0101

Race and ethnicity

Tap a square or a group below to highlight it.

Each square is about 1% of residents (roughly 1,064 people).

Hispanic or Latino residents can be of any race. All other groups exclude Hispanic residents.

U.S. Census Bureau, 2024 ACS 5-year estimates · Table B03002

Boulder Income

$87,493median household income

Median household income

$87,493

Half of households earn more, half earn less

Median earnings

$68,969

Typical yearly pay for a worker 25 or older.

Poverty rate

21.5%

About 1 in 5 residents

U.S. Census Bureau, 2024 ACS 5-year estimates · Tables S1901, S1501, S1701

Boulder Marital Status

31% of residents age 15 and older are married.

MarriedNever married
Overall
Male
Female
Marital status of residents age 15 and older
StatusOverallMaleFemale
Married31%29%32%
Never married58%62%54%
Divorced9%8%10%
Widowed2%1%4%
Separated<1%<1%<1%

U.S. Census Bureau, 2024 ACS 5-year estimates · Table S1201

Sources

14 sources

Population

American Community Survey, 2024 5-year

Additional sources