
Boulder
- County:
- Boulder County
- County Seat:
- Yes
- Area (mi²):
- 26.894
- State:
- Colorado
Boulder is a city located in Boulder County, Colorado. Boulder has a 2025 population of 104,414. It is also the county seat of Boulder County. Boulder is currently declining at a rate of -0.71% annually and its population has decreased by -3.43% since the most recent census, which recorded a population of 108,123 in 2020.
The average household income in Boulder is $140,662 with a poverty rate of 21.8%. The median age in Boulder is 28.8 years: 28.3 years for males, and 29.4 years for females.