🇺🇸 United States ZIP Code

STANDARD

04421

Castine

ZIP Code 04421 is a standard zip code serving Castine, Castine, Maine (ME), in Hancock County, United States. It has an estimated population of 1,366 with a median household income of $41,563. The area falls within the America/New_York timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Maine (ME)
County: Hancock
City: Castine
Timezone: America/New_York

Coordinates

Latitude: 44.415600
Longitude: -68.792900

Geographic Details

Land Area: 7.78 mi²
Water Area: 12.23 mi²
Population Density: 176.0 people per mi² (60th percentile)
Bounding Box: 44.462031°N, 44.354667°S, -68.762794°E, -68.853523°W

With 1,366 residents spread across 7.78 square miles, this area has a population density of 176.0 people per square mile.

Demographics

1,366

Population

30th percentile

$41,563

Median Income

30th percentile

$383,300

Median Home Value

90th percentile

7.78 mi²

Land Area

The median household income in 04421 is $41,563, and the median home value is $383,300.

Housing

704

Total Units

380

Occupied Units

54.0%

Occupancy Rate

Nearby ZIP Codes

Other zip codes in Castine, ME.

04420

Castine

Similar ZIP Codes in Maine

ZIP codes with similar median household income in Maine.

04005

Biddeford

$46,125

04009

Bridgton

$41,607

04010

Brownfield

$45,592

04015

Casco

$46,888

04020

Cornish

$43,864

04022

Denmark

$47,500

04029

Sebago

$46,349

04030

East Waterboro

$46,806

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.