🇺🇸 United States ZIP Code

STANDARD

51301

Spencer

ZIP Code 51301 is a standard zip code serving Spencer, Spencer, Iowa (IA), in Clay County, United States. It has an estimated population of 12,691 with a median household income of $47,722. The area falls within the America/Chicago timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: Iowa (IA)
County: Clay
City: Spencer
Timezone: America/Chicago

Coordinates

Latitude: 43.145100
Longitude: -95.145700

Geographic Details

Land Area: 156.26 mi²
Water Area: 0.86 mi²
Population Density: 81.0 people per mi² (50th percentile)
Bounding Box: 43.255613°N, 43.024791°S, -95.015162°E, -95.269395°W

With 12,691 residents spread across 156.26 square miles, this area has a population density of 81.0 people per square mile.

Demographics

12,691

Population

70th percentile

$47,722

Median Income

45th percentile

$112,200

Median Home Value

40th percentile

156.26 mi²

Land Area

The median household income in 51301 is $47,722, and the median home value is $112,200.

Housing

6,098

Total Units

5,600

Occupied Units

91.8%

Occupancy Rate

Similar ZIP Codes in Iowa

ZIP codes with similar median household income in Iowa.

52233

Hiawatha

$48,333

50628

Elma

$46,154

50613

Cedar Falls

$51,257

51521

Avoca

$51,500

52172

Waukon

$48,229

50238

Russell

$50,185

50220

Perry

$45,933

52639

Montrose

$49,750

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.