Colorado: Cities, Counties, ZIP Codes & Time Zones
Colorado (CO) is covered here with 448 cities, towns and communities across 64 counties and county equivalents. The capital is Denver, CO. The largest place in our data is Denver, CO, with an estimated 2,876,625 people. Use this hub to find any place in Colorado, compare sizes and densities, and look up ZIP codes and time zones.
What are the key facts about Colorado?
| State | Colorado |
|---|---|
| Abbreviation | CO |
| Capital | Denver, CO |
| Places in our data | 448 |
| Places with a city page | 122 |
| Counties | 64 |
| Time zones | Mountain time (448 places) |
| ZIP codes linked to places | 537 |
| ZIP prefix range | 800–816 |
| Median place population | 914 |
What are the largest cities in Colorado?
The 25 largest places in Colorado by estimated population are ranked below. Denver, CO leads the list, followed by Colorado Springs, CO and Aurora, CO. Select any name for ZIP codes, nearby cities and distances.
| # | City | County | Population | Per sq mi |
|---|---|---|---|---|
| 1 | Denver, CO | Denver County | 2,876,625 | 4,742 |
| 2 | Colorado Springs, CO | El Paso County | 642,413 | 2,450 |
| 3 | Aurora, CO | Adams County | 379,289 | 2,458 |
| 4 | Fort Collins, CO | Larimer County | 312,666 | 2,976 |
| 5 | Lakewood, CO | Jefferson County | 157,935 | 3,667 |
| 6 | Pueblo, CO | Pueblo County | 143,932 | 2,044 |
| 7 | Thornton, CO | Adams County | 141,464 | 3,939 |
| 8 | Grand Junction, CO | Mesa County | 139,143 | 1,608 |
| 9 | Greeley, CO | Weld County | 137,810 | 2,222 |
| 10 | Boulder, CO | Boulder County | 124,345 | 4,017 |
| 11 | Arvada, CO | Jefferson County | 121,272 | 3,126 |
| 12 | Westminster, CO | Adams County | 113,166 | 3,582 |
| 13 | Centennial, CO | Arapahoe County | 110,937 | 3,750 |
| 14 | Highlands Ranch, CO | Douglas County | 105,631 | 4,351 |
| 15 | Longmont, CO | Boulder County | 102,474 | 3,383 |
| 16 | Lafayette, CO | Boulder County | 99,645 | 3,256 |
| 17 | Loveland, CO | Larimer County | 78,877 | 2,292 |
| 18 | Broomfield, CO | Broomfield County | 70,465 | 2,134 |
| 19 | Castle Rock, CO | Douglas County | 68,484 | 1,997 |
| 20 | Commerce City, CO | Adams County | 60,336 | 1,689 |
| 21 | Parker, CO | Douglas County | 57,706 | 2,598 |
| 22 | Littleton, CO | Arapahoe County | 48,065 | 3,805 |
| 23 | Brighton, CO | Adams County | 41,554 | 1,961 |
| 24 | Security-Widefield, CO | El Paso County | 39,612 | 3,046 |
| 25 | Northglenn, CO | Adams County | 38,819 | 5,278 |
How are places in Colorado distributed by size?
The places in our Colorado data break down as follows: 1 place with over 1 million people; 3 places with 250,000 to 1 million people; 11 places with 100,000 to 250,000 people; 21 places with 25,000 to 100,000 people; 86 places with 5,000 to 25,000 people; 326 places with under 5,000 people. The median place has about 914 residents, so most communities are far smaller than the biggest cities. The densest places with a page are Glendale, CO (8,920 per sq mi), Sherrelwood, CO (7,907 per sq mi), Shaw Heights, CO (7,892 per sq mi), Edgewater, CO (7,677 per sq mi), Cherry Creek, CO (7,480 per sq mi). The least dense are Black Forest, CO (140), Edwards, CO (350), Pagosa Springs, CO (417), Battlement Mesa, CO (440), Pueblo West, CO (451). Density labels are explained in our density guide.
Which counties are in Colorado?
Colorado has 64 counties or county equivalents in our data. The links below open the 34 that contain at least one place with a full page. Counties are identified by five-digit FIPS codes, which our county guide explains.
What ZIP codes does Colorado use?
The places in Colorado are linked to 537 ZIP codes. Their three-digit prefixes run from 800 to 816, and the first digit is 8, pointing to the Mountain West (Arizona, Colorado, Idaho, Nevada, New Mexico, Utah and Wyoming). Prefixes reveal the regional mail sorting hub, not a county or city. Try the ZIP code lookup to match a code to a place.
What time zones does Colorado use?
Places in Colorado fall in these zones in our data: Mountain time (448 places). The state is entirely in one zone in our data. Read US time zones explained for how daylight saving time applies.
Which states are near Colorado?
Measured between the average locations of their places, the closest states are Wyoming (278 mi northwest), New Mexico (318 mi south), Utah (348 mi west), Nebraska (392 mi northeast), Kansas (430 mi east). Distances are straight-line and rough, since state shapes differ greatly.
Where to go next
Figures are estimates from a compiled dataset; confirm official numbers with the Census Bureau.