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Where am ILOCATED

Boulder County, Colorado

Boulder County, Colorado, has 328,560 residents (July 2025 estimate). Its county seat is Boulder. It uses Mountain Time and covers 726 sq mi (1,881 km²) of land.

DenverColorado SpringsAurora
Boulder County in Colorado
Broomfield CountyBoulderLongmontErieLafayette
Boulder County and its neighbors (simplified outlines). Open in OpenStreetMap ↗
Resident population, July 2025
328,560
Land area
726 sq mi (1,881 km²)
County seat or government
Boulder
Time zone
Mountain TimeUTC-07:00 in January; UTC-06:00 in July
Median household income
$103,994 ± $2,268
Median home value
$756,300 ± $14,324
Median rent, with utilities
$1,966 ± $30
Homes lived in by their owners
62% ± 0.8 points
County type
County
Metro or micro area
Boulder, CO metro areaCentral county
Water area
14.1 sq mi (36.4 km²)
State
Colorado
County code (FIPS)
08013
Coordinates (central point)
40.094971, -105.397710
Open this point in the location finder

These coordinates mark a central point for the area, not a street address. Income, home value, rent and homes lived in by their owners: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, ± margin at 90% confidence; checked on October 13, 2026.

Time zones in Boulder County

Time zoneLocal time and UTC offsetNext clock change
Mountain TimeAmerica/DenverUTC-07:00 in January; UTC-06:00 in July. Enable JavaScript for the live clock.Enable JavaScript for upcoming changes.

Near a time-zone line, check where you are with the time-zone finder. Your phone’s setting can differ.

ZIP Code areas, largest first

  1. 8050463,451 people
  2. 8002054,201 people
  3. 8050144,147 people
  4. 8051639,048 people
  5. 8050335,846 people
  6. 8002734,127 people
  7. 8002632,701 people
  8. 8030229,569 people
  9. 8030425,383 people
  10. 8030125,007 people
  11. 8030324,996 people
  12. 8040320,732 people
All 23
  1. 8051318,271 people
  2. 8030516,291 people
  3. 803107,692 people
  4. 805404,642 people
  5. 804663,599 people
  6. 80510663 people
  7. 80455501 people
  8. 80481484 people
  9. 80025138 people
  10. 804710 people
  11. 805440 people

23 ZIP Code areas overlap Boulder County. People counts are 2020–2024 estimates for each whole ZIP area. Mailing ZIPs can differ; check an address with USPS ZIP Code Lookup.

Official county information

We don’t have a website for this county yet. The US government’s local-office directory ↗ lists its offices. A geographic lookup cannot determine eligibility, tax liability or a court obligation.

School districts in Boulder County, largest first

  1. Boulder Valley School District RE-2238,927 people
  2. St. Vrain Valley School District RE 1J200,423 people
  3. Thompson School District R-2J132,014 people
  4. Estes Park School District R-311,940 people

Districts with land in the county; a district can cross county lines. People counts are American Community Survey 2020–2024 5-year estimates. A district boundary doesn’t decide which school a student attends.

Cities, towns and communities, largest first

These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.

  1. Boulder, Colorado (city)106,433 people
  2. Longmont, Colorado (city)99,406 people
  3. Erie, Colorado (town)33,808 people
  4. Lafayette, Colorado (city)30,602 people
  5. Louisville, Colorado (city)20,786 people
  6. Superior, Colorado (town)13,305 people
  7. Gunbarrel, Colorado (CDP)10,051 people
  8. Niwot, Colorado (CDP)3,447 people
  9. Coal Creek, Colorado (CDP)2,346 people
  10. Lyons, Colorado (town)1,838 people
  11. Nederland, Colorado (town)1,655 people
  12. Allenspark, Colorado (CDP)825 people
All 34
  1. Lazy Acres, Colorado (CDP)778 people
  2. Paragon Estates, Colorado (CDP)667 people
  3. Altona, Colorado (CDP)587 people
  4. Pine Brook Hill, Colorado (CDP)543 people
  5. Sugarloaf, Colorado (CDP)474 people
  6. Eldora, Colorado (CDP)465 people
  7. St. Ann Highlands, Colorado (CDP)453 people
  8. Tall Timber, Colorado (CDP)382 people
  9. Sunshine, Colorado (CDP)330 people
  10. Jamestown, Colorado (town)324 people
  11. Eldorado Springs, Colorado (CDP)320 people
  12. Crisman, Colorado (CDP)268 people
  13. Bark Ranch, Colorado (CDP)199 people
  14. Seven Hills, Colorado (CDP)183 people
  15. Mountain Meadows, Colorado (CDP)180 people
  16. Gold Hill, Colorado (CDP)178 people
  17. Ward, Colorado (town)103 people
  18. Glendale, Colorado (CDP)69 people

See all 34 cities, towns and communities in Boulder County, largest first

Bordering areas, nearest first

Distances are straight lines between map points.

  1. Gilpin County, Colorado18 mi southwest
  2. Broomfield County, Colorado21 mi southeast
  3. Jefferson County, Colorado37 mi south
  4. Grand County, Colorado38 mi west
  5. Larimer County, Colorado39 mi north
  6. Weld County, Colorado62 mi northeast

Before using this answer on a form

Use a precise point for address-level questions. A device accuracy circle can cross a boundary; confirm tax, voting or jury details with the responsible office.

Find the county where you are now, check its ZIP area, or check the time zone where you are.

See this county on Census.gov ↗

Areas that only touch the edge

These areas meet the boundary only along a sliver. Most addresses here are not in them; for an address near the line, check with the county.