ZIP Code 78665
standardSource:
Round Rock · Williamson County · Texas
- Population
- 35,985
- Median income
- $122,680
- Median home value
- $474,100
- Bachelor's or higher
- 53.6%
- Land area
- 48.6 sq mi
741/sq mi
▲ 61% vs US
higher than 91% of US ZIPs
▲ 70% vs US
higher than 86% of US ZIPs
Median age 35.5
Chicago
ZIP code 78665 in Round Rock, Texas has a population of 35,985. The median household income is $122,680, which is 61% above the national average. Median home value is $474,100, 70% above the US average. 53.6% of residents hold a bachelor's degree or higher.
ZIP code 78665 is classified by USPS as a standard delivery area and covers roughly 48.6 square miles in Round Rock, Williamson County, Texas. The area is home to 35,985 residents, producing a population density of 741 people per square mile, and falls within the Chicago time zone. These USPS and Census boundary values drive every downstream statistic on this page, including the benchmarks that compare 78665 against Texas and the nation.
On the economic side, the median household income for ZIP 78665 sits at $122,680 (62% above the Texas average), while per-capita income is $56,191. The poverty rate stands at 4.7% and the unemployment rate at 3.4%. On housing, the median home value is $474,100 (92% above the state average) with median rent at $1,938 per month, and 61.4% of occupied units are owner-occupied, a direct signal of whether 78665 behaves more like a homeowner neighborhood or a renter-heavy ZIP.
Education and household profile round out the picture: 53.6% of adults hold a bachelor's degree or higher, the median age is 35.5, and the average commute is 28 minutes. We also surface 10 nearby ZIP codes within roughly 10 miles and 6 additional ZIPs sharing Williamson County, so you can benchmark 78665 against its immediate geography rather than a national average alone. Every figure is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates, HUD Fair Market Rents, and FHFA Home Price Index data, no estimates, no proprietary scoring. Verify with HUD →
Top industries in ZIP 78665
Top 5 sectors by establishment count
Which industries have the most business establishments in ZIP 78665.
- Professional, scientific, and technical services
Professional, scientific, and technical services
163 establishments
- Health care and social assistance
Health care and social assistance
145 establishments
- Construction
Construction
101 establishments
- Other services (except public administration)
Other services (except public administration)
94 establishments
- Accommodation and food services
Accommodation and food services
90 establishments
What this shows Establishment counts come from the Census ZIP Code Business Patterns program, which counts physical business locations rather than employees or revenue.
Source: U.S. Census Bureau, American Community Survey 5-Year Estimates + ZIP Code Business Patterns + HUD FMR + FHFA HPI ACS demographics, ZBP business establishments, HUD Fair Market Rents, FHFA HPI for ZIP 78665, Round Rock, TX · 2023 Census ACS 5-Year Estimates use a rolling 60-month sample for stable small-geography estimates; ZBP updated annually; HUD FMR + FHFA HPI updated quarterly/annually.
Quick Facts
35,985
Population
48.6
Area (sq mi)
741
People / sq mi
Chicago
Time Zone
standard
ZIP Type
Who lives in ZIP 78665?
35.5
Median Age
50.3%
Male
49.7%
Female
17.6%
Foreign-Born
Hispanic or Latino is an ethnicity category from the Census Bureau and may overlap with other categories above.
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
How much do residents earn?
$122,680
Median Household Income
+62% vs state
$56,191
Per Capita Income
4.7%
Poverty Rate
3.4%
Unemployment Rate
27.8 min
Mean Commute Time
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What is the education profile here?
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
What does housing look like?
25,598
Total Housing Units
24,162
Occupied Units
1,436
Vacant Units
2.73
Avg Household Size
Occupancy Type
$474,100
Median Home Value
+92% vs state
$1,938
Median Rent
2010
Median Year Built
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023)
How have home values changed over time?
FHFA House Price Index, annual appreciation data based on repeat sales and appraisals
-5.5%
YoY Change (2024)
266
HPI Index (2000 = 100)
+166%
Total Change Since 2000
Home values in ZIP 78665 have decreased 5.5% over the past year (2024). Since 2000, this ZIP has seen +166% cumulative appreciation.
| Year | Annual Change | HPI Index |
|---|---|---|
| 2020 | +3.3% | 188 |
| 2021 | +26.1% | 237 |
| 2022 | +24.0% | 295 |
| 2023 | -4.3% | 282 |
| 2024 | -5.5% | 266 |
Source: Federal Housing Finance Agency (FHFA) House Price Index, All-Transactions, Five-Digit ZIP Codes (Developmental Index). Index base = 100 in year 2000. Data through 2024. ZIP codes with few transactions may show missing values.
What businesses operate in this ZIP?
Census Bureau data shows 981 business establishments in ZIP 78665, employing approximately 16,807 people with a combined annual payroll of $949,925,000.
981
Businesses
16,807
Employees
$949.9M
Annual Payroll
15
Industry Sectors
| Industry | Establishments | % of Total |
|---|---|---|
| Professional, scientific, and technical services | 163 | 16.6% |
| Health care and social assistance | 145 | 14.8% |
| Construction | 101 | 10.3% |
| Other services (except public administration) | 94 | 9.6% |
| Accommodation and food services | 90 | 9.2% |
| Retail trade | 83 | 8.5% |
| Administrative and support and waste management and remediation services | 67 | 6.8% |
| Real estate and rental and leasing | 60 | 6.1% |
| Finance and insurance | 40 | 4.1% |
| Wholesale trade | 31 | 3.2% |
| Manufacturing | 24 | 2.5% |
| Transportation and warehousing | 23 | 2.3% |
| Information | 20 | 2.0% |
| Educational services | 19 | 1.9% |
| Arts, entertainment, and recreation | 17 | 1.7% |
Source: U.S. Census Bureau, ZIP Code Business Patterns (ZBP), 2023. Employment figures may include noise for disclosure avoidance.
Nearby ZIP Codes
Want a side-by-side? Compare 78665 vs 78664 →
| ZIP Code | City | Population | Distance |
|---|---|---|---|
| 78664 | Round Rock, TX | 52,932 | 2.8 mi |
| 78681 | Round Rock, TX | 50,606 | 4.9 mi |
| 78634 | Hutto, TX | 22,791 | 6.0 mi |
| 78728 | Austin, TX | 20,299 | 6.7 mi |
| 78660 | Pflugerville, TX | 68,789 | 7.6 mi |
| 78717 | Austin, TX | 22,538 | 7.6 mi |
| 78626 | Georgetown, TX | 25,996 | 8.8 mi |
| 78727 | Austin, TX | 26,689 | 9.1 mi |
| 78729 | Austin, TX | 27,108 | 9.0 mi |
| 78628 | Georgetown, TX | 23,727 | 9.2 mi |
More ZIP Codes in Williamson County
Related Areas
Frequently Asked Questions
What county is ZIP code 78665 in? ▼
What is the population of ZIP code 78665? ▼
What is the median household income in ZIP 78665? ▼
What is the average home value in ZIP 78665? ▼
What is the demographic makeup of ZIP 78665? ▼
How many businesses are in ZIP code 78665? ▼
What are the main industries in ZIP code 78665? ▼
How have home values changed in ZIP code 78665? ▼
What is the education level in ZIP code 78665? ▼
What is the average commute time in ZIP 78665? ▼
What percentage of residents own vs. rent in ZIP 78665? ▼
What is the poverty rate in ZIP code 78665? ▼
ZIP Code Research Guides
Official Data Resources for Round Rock, TX
Verify and explore additional data for this area using these official government sources.
Source: U.S. Census Bureau, ACS 5-Year Estimates (2023). Business data: Source: Census ZIP Code Business Patterns (ZBP) 2023. Home value trends: Source: FHFA House Price Index (HPI), Five-Digit ZIP Codes.
PlainZIP is not affiliated with the U.S. Census Bureau or any government agency.
Read our methodology , how this data is sourced, computed, and verified.