78665 ZIP Code — Round Rock, TX

Williamson County, Texas

ZIP code 78665 is located in Round Rock, Texas, within Williamson County. It covers approximately 24.08 square miles and serves a population of 61,640 residents. This is a standard ZIP code in the Central (CT) timezone, served by area code 512/737.

About ZIP code 78665

The housing stock consists of predominantly single-family detached homes. Much of the housing stock is relatively new, reflecting recent development activity. Median home value is $381,300. Owner-occupancy sits near the national average at 66%.

Median household income is $113,365. The poverty rate of 5% is below the national average.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 29 minutes is near the national average. Remote work is prevalent — 23% of workers work from home.

Educational attainment is high — 51% of residents hold a bachelor's degree or higher, well above the national average of 33%.

Overall, ZIP code 78665 reflects a community defined by a highly educated population and a high rate of remote workers.

61,640

population

24.08

sq mi land

Standard

ZIP type

Central (CT)

timezone

78665 ZIP code map

Cities in ZIP code 78665

Below are the cities the US Postal Service accepts for ZIP code 78665. Using any city not on this list may result in mail delivery delays.

City	Status
Round Rock	Preferred

Nearby ZIP codes

78682 Round Rock (2.2 mi) 78664 Round Rock (2.9 mi) 78681 Round Rock (5 mi) 78681 Round Rock (5 mi) 78634 Hutto (5.7 mi) 78728 Austin (6.8 mi) 78660 Pflugerville (7.5 mi) 78717 Austin (7.9 mi) 78729 Austin (8.8 mi) 78727 Austin (8.9 mi) 78626 Georgetown (9.3 mi) 78628 Georgetown (9.8 mi)

Demographics updated 07/2026

Population
Total population	61,640
Population density	2,560 / sq mi
State FIPS	48
County FIPS	491

Geography
Land area	24.08 sq mi
Water area	0.36 sq mi
Latitude	30.5402
Longitude	-97.6470
Timezone	Central (CT)
Area code	512/737

Total population by age

Gender

Race & ethnicity

Economics updated 07/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	17.0%	23.0%	39.5%
$50k – $100k	31.7%	30.5%	30.1%
$100k – $200k	35.5%	34.7%	22.6%
Over $200k	15.8%	11.8%	7.8%

Demographics & statistics

61,640

Population

2,560

People per sq mi

35.4

Median age

$113,365

Median household income

$49,794

Per capita income

$381,300

Median home value

$1,812

Median monthly rent

65.7%

Home ownership

4.8%

Poverty rate

3.8%

Unemployment

15,927

Housing units

50.9%

Bachelor's or higher

Age distribution

Male Female

2,369

Under 5

2,401

2,581

5–9

2,615

2,316

10–14

2,347

2,003

15–19

2,030

1,709

20–24

1,732

4,110

25–34

4,164

5,820

35–44

5,897

3,783

45–54

3,832

1,698

55–59

1,720

1,234

60–64

1,250

2,043

65–74

2,069

689

75–84

699

263

85+

266

← Male

Female →

Age summary

Group	Count	%
Under 18	16,947	27.5%
18 and over	44,693	72.5%
65 and over	6,029	9.8%
Median age	35.4 years

Race & ethnicity

White 51.1%

Two or more races 13.9%

Hispanic or Latino 13.3%

Black or African American 10%

Asian 7.6%

Other race 3.4%

American Indian / Alaska Native 0.3%

Native Hawaiian / Pacific Islander 0.3%

Group	Count	%
White	36,352	51.1%
Two or more races	9,893	13.9%
Hispanic or Latino	9,431	13.3%
Black or African American	7,137	10%
Asian	5,415	7.6%
Other race	2,382	3.4%
American Indian / Alaska Native	231	0.3%
Native Hawaiian / Pacific Islander	230	0.3%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	17.0%	23.0%	39.5%
$50k – $100k	31.7%	30.5%	30.1%
$100k – $200k	35.5%	34.7%	22.6%
Over $200k	15.8%	11.8%	7.8%

Under $10k 3.2%

$10k–$15k 0.9%

$15k–$25k 1.5%

$25k–$35k 4.2%

$35k–$50k 6.7%

$50k–$75k 14.2%

$75k–$100k 11.6%

$100k–$150k 25.5%

$150k–$200k 15.3%

$200k+ 17.0%

Range	% of households
Under $10k	3.2%
$10k–$15k	0.9%
$15k–$25k	1.5%
$25k–$35k	4.2%
$35k–$50k	6.7%
$50k–$75k	14.2%
$75k–$100k	11.6%
$100k–$150k	25.5%
$150k–$200k	15.3%
$200k+	17.0%
Median income	$113,365

Housing

Home values

Under $50k 1.1%

$50k–$100k 0.2%

$100k–$150k 0.9%

$150k–$200k 2.6%

$200k–$300k 19.9%

$300k–$500k 50.0%

$500k–$1M 24.5%

$1M+ 0.8%

Housing overview

Metric	Value
Median home value	$381,300
Median rent / month	$1,812
Owner occupied	65.7%
Renter occupied	34.3%
Vacant	6.0%
Single-family detached	76.3%
Large apartment buildings	13.3%
Mobile homes	0.0%
Median rooms	6.2
Avg household size (owned)	2.93

Year built

Era	%
2020 or later	4.6%
2010–2019	41.0%
2000–2009	37.6%
1990–1999	12.6%
1980–1989	1.6%
1970–1979	1.7%
1960–1969	0.3%
1950–1959	0.3%
1940–1949	0.2%
1939 or earlier	0.1%

Bedrooms

Size	% of units
No bedroom (studio)	1.3%
1 bedroom	9.5%
2 bedrooms	12.1%
3 bedrooms	35.7%
4 bedrooms	34.0%
5+ bedrooms	7.3%

Vehicles per household

Vehicles	% of households
No vehicle	1.7%
1 vehicle	27.8%
2 vehicles	50.3%
3 or more	20.2%

Heating fuel

Fuel type	%
Utility gas	57.1%
Electricity	42.0%
Propane / LP gas	0.4%
Fuel oil	0.3%
No fuel used	0.2%

Households & families

Household type	Count	%
Married-couple family	13,709	62.0%
Cohabiting couple	1,264	5.7%
Male householder, no spouse	2,504	11.3%
Female householder, no spouse	4,628	20.9%
Households with children under 18	9,945	45.0%
Households with seniors (65+)	4,139	18.7%
Average household size	2.78

Marital status

Status	Male	Female
Never married	29.0%	22.6%
Married	61.5%	58.5%
Separated	0.7%	0.9%
Widowed	2.1%	4.6%
Divorced	6.7%	13.5%

Education

Less than 9th grade 1.6%

Some HS, no diploma 1.7%

HS graduate 15.7%

Some college, no degree 19.8%

Associate's degree 10.3%

Bachelor's degree 31.8%

Graduate / professional 19.1%

Metric	%
HS diploma or higher	96.6%
Bachelor's or higher	50.9%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	1,106	6.7%
Kindergarten	856	5.2%
Elementary school	7,592	46.0%
High school	3,253	19.7%
College / grad school	3,706	22.4%

Employment

Industry of employment

Education & healthcare 22.1%

Professional & management 18.5%

Retail trade 11.0%

Manufacturing 10.9%

Finance & real estate 7.3%

Public administration 6.8%

Arts, food & hospitality 6.7%

Transportation & utilities 4.3%

Construction 3.9%

Other services 3.7%

Wholesale trade 2.7%

Information 1.8%

Agriculture & mining 0.2%

Occupation

Category	%
Management, business & arts	52.3%
Service	12.6%
Sales & office	23.7%
Natural resources & construction	3.1%
Production & transportation	8.3%

Employment type

Type	%
Private sector	81.3%
Government	14.5%
Self-employed	4.2%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	65.9%
Carpool	9.6%
Public transit	0.2%
Walk	0.3%
Work from home	22.6%
Other means	1.4%
Avg commute (minutes)	29.0

Poverty

All people 4.8%

Under 18 years 4.7%

18 and over 4.8%

Married-couple families 2.3%

Female-led households 9.0%

Income support

Source	% of households
Social Security	19.7%
Retirement income	17.9%
Supplemental Security	3.0%
Cash public assistance	0.3%
Food stamps / SNAP	3.0%

Health indicators

Condition	%
Obesity	30.8%
High blood pressure	24.6%
High cholesterol	28.6%
Diabetes	7.2%
Heart disease	3.2%
Stroke	1.6%
Asthma	8.4%
Arthritis	16.1%
Kidney disease	1.7%
Pulmonary disease	3.5%
Cancer	3.9%

Behavior / access	%
Smoking	13.6%
Binge drinking	22.2%
No physical activity	17.6%
Less than 7 hrs sleep	32.7%
Depression	21.0%
Fair or poor health	10.1%
Poor mental health	14.2%
Poor physical health	7.4%
No health insurance	21.4%
Visited doctor (checkup)	67.5%
Visited dentist	63.8%
Cholesterol screening	89.0%
Teeth loss	8.8%

Veterans & disability

Veterans	Count	%
Civilian veterans	3,883	8.7%

Disability	%
Any disability	10.0%
Under 18	7.2%
18–64 years	9.3%
65 and over	22.2%

Health insurance coverage

Type	%
Private insurance	84.4%
Public insurance	16.9%
No insurance	7.6%
Uninsured under 19	5.4%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	56,870	92.3%
Spanish	3,625	6.4%
Other Indo-European	1,895	3.3%
Asian & Pacific Islander	470	0.8%
Other languages	1,123	2.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	52,317	84.9%
Born in same state	51,022	82.8%
Born in different state	27,289	44.3%
Foreign born	1,295	2.1%
Naturalized citizen	9,323	15.1%
Not a US citizen	6,068	65.1%

Ancestry

Ancestry	Count	%
French	7,537	12.2%
Italian	4,942	8%
Arab	2,502	4.1%
English	688	1.1%
Polish	659	1.1%

Ancestry	Count	%
Dutch	418	0.7%
German	410	0.7%
Irish	150	0.2%
Norwegian	49	0.1%

Technology access

Metric	% of households
Computer access	35.9%
Internet access	99.4%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 78665

What part of Round Rock is ZIP code 78665?

ZIP code 78665 covers a portion of Round Rock, Texas, within Williamson County.

What county is ZIP code 78665 in?

ZIP code 78665 falls within Williamson County, Texas.

How educated is the population of ZIP code 78665?

51% of residents hold a bachelor's degree or higher — well above the national average of ~33%, reflecting a highly educated population.

What is the typical home value in ZIP code 78665?

The median home value in ZIP code 78665 is $381,300.

What is the median household income in ZIP code 78665?

The median household income in ZIP code 78665 is $113,365, above the national median of ~$75,000.

What is the population of ZIP code 78665?

ZIP code 78665 has an estimated population of 61,640 residents, with a density of 2,560 people per square mile.

What timezone is ZIP code 78665 in?

ZIP code 78665 observes the CST timezone.