| Area Code | 720 |
| State | Colorado |
| Current Time in Area Code 720 | 720> MST |
| Timezone | Mountain Standard Time |
| Regional Market Area | Metro Denver |
| Metro Area(s) | Boulder, CO Denver-Aurora-Lakewood, CO |
| Population (2020) | 3251127 |
| Adjacent Area Codes | 303,719,970,983 |
| Overlay Area Codes | 303,983 |
| Adams County |
| Arapahoe County |
| Boulder County |
| Broomfield County |
| Clear Creek County |
| Denver County |
| Douglas County |
| Gilpin County |
| Jefferson County |