Boulder County Flag

Boulder County

State:
Colorado
County Seat:
Boulder

Boulder County's estimated 2025 population is 325,815 with a growth rate of -0.16% in the past year according to the most recent United States census data. Boulder County is the 9th largest county in Colorado. The 2010 population was 295,056 and has seen a growth of 10.42% since that time.

325,815
Total Population
449
Population Density (mi²)
9
Population Rank (State)
-508 -0.16%
Annual Population Growth

Boulder County Population

Demographics

Economics and Income Statistics