🇺🇸 United States ZIP Code

STANDARD

80109

Castle Rock

ZIP Code 80109 is a standard zip code serving Castle Rock, Castle Rock, Colorado (CO), in Douglas County, United States. It has an estimated population of 17,219 with a median household income of $108,781. The area falls within the America/Denver timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Colorado (CO)
County: Douglas
City: Castle Rock
Timezone: America/Denver

Coordinates

Latitude: 39.364300
Longitude: -104.901400

Geographic Details

Land Area: 26.37 mi²
Population Density: 653.0 people per mi² (75th percentile)
Bounding Box: 39.427902°N, 39.296831°S, -104.858652°E, -104.951223°W

With 17,219 residents spread across 26.37 square miles, this area has a population density of 653.0 people per square mile.

Demographics

17,219

Population

75th percentile

$108,781

Median Income

95th percentile

$325,200

Median Home Value

85th percentile

26.37 mi²

Land Area

The median household income in 80109 is $108,781, and the median home value is $325,200. This places the area in the top 25% nationally for household income.

Housing

5,778

Total Units

5,529

Occupied Units

95.7%

Occupancy Rate

Nearby ZIP Codes

Other zip codes in Castle Rock, CO.

80104

Castle Rock

80108

Castle Rock

Similar ZIP Codes in Colorado

ZIP codes with similar median household income in Colorado.

80132

Monument

$107,475

80106

Elbert

$97,321

80924

Colorado Springs

$110,222

80126

Littleton

$112,455

80138

Parker

$99,316

80016

Aurora

$101,280

80018

Aurora

$95,843

80023

Broomfield

$110,553

Frequently Asked Questions

What information is available for each ZIP code?

Each ZIP code page shows city, state, county, geographic coordinates, timezone, population, median household income, median home value, housing units, land area, population density, commute time, educational attainment, area codes, and ZIP code type (Standard, PO Box, or Unique).

What are the different types of ZIP codes?

There are three types of ZIP codes: Standard (residential and commercial delivery areas), PO Box (assigned to post office box sections), and Unique (assigned to a single high-volume address like a government agency or large company). Standard ZIP codes are the most common.

How often is ZIP code data updated?

ZIP code assignments are updated quarterly by the USPS. Demographic data comes from the US Census Bureau's American Community Survey (ACS), which releases new 5-year estimates annually. ZipFYI updates its data to reflect the latest available information.

What is population density and why does it matter?

Population density measures the number of people per square mile in a ZIP code area. It helps identify urban vs. rural areas, affects real estate values, impacts service availability, and is used in market analysis. Dense urban ZIP codes may have 50,000+ people per square mile.

How are ZIP code boundaries determined?

ZIP code boundaries are determined by the USPS based on mail delivery routes, not political or geographic boundaries. They follow carrier routes and may cross city, county, or even state lines. Boundaries can change when the USPS reorganizes delivery operations.

What does median household income tell me about a ZIP code?

Median household income is the middle value when all household incomes in a ZIP code are sorted. Half of households earn more and half earn less. It is a better indicator of typical earnings than average income, which can be skewed by very high or very low outliers.