🇺🇸 United States ZIP Code

STANDARD

92078

San Marcos

ZIP Code 92078 is a standard zip code serving San Marcos, San Marcos, California (CA), in San Diego County, United States. It has an estimated population of 42,906 with a median household income of $54,441. The area falls within the America/Los_Angeles timezone.

Median Household Income vs. National Average

Location

Country: 🇺🇸 United States
State / Province: California (CA)
County: San Diego
City: San Marcos
Timezone: America/Los_Angeles

Coordinates

Latitude: 33.119300
Longitude: -117.185000

Geographic Details

Land Area: 16.70 mi²
Water Area: 0.11 mi²
Population Density: 2569.0 people per mi² (85th percentile)
Bounding Box: 33.157806°N, 33.085870°S, -117.123407°E, -117.231258°W

With 42,906 residents spread across 16.70 square miles, this area has a population density of 2569.0 people per square mile.

Demographics

42,906

Population

95th percentile

$54,441

Median Income

60th percentile

$369,700

Median Home Value

90th percentile

16.70 mi²

Land Area

The median household income in 92078 is $54,441, and the median home value is $369,700.

Housing

17,034

Total Units

15,990

Occupied Units

93.9%

Occupancy Rate

Nearby ZIP Codes

Other zip codes in San Marcos, CA.

92069

San Marcos

92079

San Marcos

92096

San Marcos

Similar ZIP Codes in California

ZIP codes with similar median household income in California.

92116

San Diego

$53,448

95112

San Jose

$48,370

90740

Seal Beach

$51,211

92549

Idyllwild

$58,924

95695

Woodland

$51,158

95457

Lower Lake

$46,277

93041

Port Hueneme

$52,814

95386

Waterford

$52,560

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.