Larimer County, CO and Boulder County, CO, compared
Larimer County, CO had 377,292 people on July 1, 2025, and Boulder County, CO 328,560, in the Census Bureau’s estimates.
Side by side
| Measure | Larimer County, CO | Boulder County, CO |
|---|---|---|
| Population, July 2025The Census Bureau's Vintage 2025 estimate. | 377,292 | 328,560 |
| Change since July 2020As a share of the first July. | +4.8% | −0.7% |
| Births less deathsOver the five full years to July 2025. | +1,479 | +1,308 |
| Moves from abroadNet international migration, as the Bureau estimates it. | +3,716 | +6,827 |
| Moves from elsewhere in the countryNet domestic migration. | +11,855 | −10,148 |
Each on its own
Data retrieved
Sources
- Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
- American Community Survey 5-year estimates — table-based Summary File · U.S. Government work