78664 ZIP Code — Round Rock, TX
Williamson County, Texas
ZIP code 78664 is located in Round Rock, Texas, within Williamson County. It covers approximately 16.61 square miles and serves a population of 62,168 residents. This is a standard ZIP code in the Central (CT) timezone, served by area code 512/737.
About ZIP code 78664
The housing stock consists of a mix of housing types. Most homes were built in the 1990s, giving the area an established character. Median home value is $281,800. Owner-occupancy sits near the national average at 55%.
Median household income is $83,599.
The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 24 minutes is near the national average.
Educational attainment is near the national average, with 32% of residents holding a bachelor's degree or higher.
62,168
population
16.61
sq mi land
Standard
ZIP type
Central (CT)
timezone
78664 ZIP code map
Cities in ZIP code 78664
Below are the cities the US Postal Service accepts for ZIP code 78664. Using any city not on this list may result in mail delivery delays.
| City | Status |
|---|---|
| Round Rock | Acceptable |
| Round Rock | Preferred |
Nearby ZIP codes
78682 Round Rock (2.5 mi)
78665 Round Rock (2.9 mi)
78660 Pflugerville (4.5 mi)
78728 Austin (5.3 mi)
78681 Round Rock (5.9 mi)
78681 Round Rock (5.9 mi)
78634 Hutto (6 mi)
78727 Austin (7.4 mi)
78729 Austin (8.2 mi)
78717 Austin (8.2 mi)
78753 Austin (8.8 mi)
78758 Austin (9.3 mi)
Demographics
updated 06/2026
| Population | |
|---|---|
| Total population | 62,168 |
| Population density | 3,743 / sq mi |
| State FIPS | 48 |
| County FIPS | 491 |
| Geography | |
|---|---|
| Land area | 16.61 sq mi |
| Water area | 0.09 sq mi |
| Latitude | 30.5006 |
| Longitude | -97.6302 |
| Timezone | Central (CT) |
| Area code | 512/737 |
Total population by age
Gender
Race & ethnicity
Economics
updated 06/2026
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 28.5% | 23.0% | 39.5% |
| $50k – $100k | 34.8% | 30.5% | 30.1% |
| $100k – $200k | 30.0% | 34.7% | 22.6% |
| Over $200k | 6.7% | 11.8% | 7.8% |
Demographics & statistics
62,168
Population
3,743
People per sq mi
34.5
Median age
$83,599
Median household income
$37,780
Per capita income
$281,800
Median home value
$1,500
Median monthly rent
54.6%
Home ownership
10.1%
Poverty rate
4.2%
Unemployment
13,445
Housing units
32.4%
Bachelor's or higher
Age distribution
Male
Female
1,758
Under 5
1,905
1,662
5–9
1,800
2,032
10–14
2,202
2,427
15–19
2,630
2,283
20–24
2,474
5,069
25–34
5,491
4,543
35–44
4,921
4,196
45–54
4,547
1,671
55–59
1,811
1,334
60–64
1,445
1,797
65–74
1,947
768
75–84
833
299
85+
323
← Male
Female →
Age summary
| Group | Count | % |
|---|---|---|
| Under 18 | 14,615 | 23.5% |
| 18 and over | 47,553 | 76.5% |
| 65 and over | 5,967 | 9.6% |
| Median age | 34.5 years | |
Race & ethnicity
White
50.9%
Two or more races
14.1%
Hispanic or Latino
14%
Black or African American
12.4%
Asian
4.1%
Other race
3.8%
American Indian / Alaska Native
0.6%
| Group | Count | % |
|---|---|---|
| White | 36,830 | 50.9% |
| Two or more races | 10,175 | 14.1% |
| Hispanic or Latino | 10,147 | 14% |
| Black or African American | 9,001 | 12.4% |
| Asian | 2,958 | 4.1% |
| Other race | 2,776 | 3.8% |
| American Indian / Alaska Native | 428 | 0.6% |
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 28.5% | 23.0% | 39.5% |
| $50k – $100k | 34.8% | 30.5% | 30.1% |
| $100k – $200k | 30.0% | 34.7% | 22.6% |
| Over $200k | 6.7% | 11.8% | 7.8% |
Under $10k
3.4%
$10k–$15k
1.7%
$15k–$25k
3.8%
$25k–$35k
4.6%
$35k–$50k
12.6%
$50k–$75k
18.3%
$75k–$100k
13.5%
$100k–$150k
21.9%
$150k–$200k
11.2%
$200k+
9.1%
| Range | % of households |
|---|---|
| Under $10k | 3.4% |
| $10k–$15k | 1.7% |
| $15k–$25k | 3.8% |
| $25k–$35k | 4.6% |
| $35k–$50k | 12.6% |
| $50k–$75k | 18.3% |
| $75k–$100k | 13.5% |
| $100k–$150k | 21.9% |
| $150k–$200k | 11.2% |
| $200k+ | 9.1% |
| Median income | $83,599 |
Housing
Home values
Under $50k
3.5%
$50k–$100k
0.7%
$100k–$150k
4.0%
$150k–$200k
6.4%
$200k–$300k
43.4%
$300k–$500k
30.0%
$500k–$1M
11.5%
$1M+
0.6%
Housing overview
| Metric | Value |
|---|---|
| Median home value | $281,800 |
| Median rent / month | $1,500 |
| Owner occupied | 54.6% |
| Renter occupied | 45.4% |
| Vacant | 3.6% |
| Single-family detached | 62.3% |
| Large apartment buildings | 11.7% |
| Mobile homes | 0.1% |
| Median rooms | 5.2 |
| Avg household size (owned) | 2.79 |
Year built
| Era | % |
|---|---|
| 2020 or later | 0.3% |
| 2010–2019 | 18.3% |
| 2000–2009 | 23.0% |
| 1990–1999 | 23.3% |
| 1980–1989 | 22.6% |
| 1970–1979 | 9.4% |
| 1960–1969 | 1.4% |
| 1950–1959 | 1.0% |
| 1940–1949 | 0.4% |
| 1939 or earlier | 0.4% |
Bedrooms
| Size | % of units |
|---|---|
| No bedroom (studio) | 1.4% |
| 1 bedroom | 12.5% |
| 2 bedrooms | 21.5% |
| 3 bedrooms | 43.8% |
| 4 bedrooms | 18.0% |
| 5+ bedrooms | 2.6% |
Vehicles per household
| Vehicles | % of households |
|---|---|
| No vehicle | 2.7% |
| 1 vehicle | 33.9% |
| 2 vehicles | 42.5% |
| 3 or more | 20.9% |
Heating fuel
| Fuel type | % |
|---|---|
| Utility gas | 48.0% |
| Electricity | 50.8% |
| Propane / LP gas | 0.4% |
| Solar | 0.1% |
| No fuel used | 0.7% |
Households & families
| Household type | Count | % |
|---|---|---|
| Married-couple family | 11,047 | 48.0% |
| Cohabiting couple | 1,642 | 7.1% |
| Male householder, no spouse | 3,697 | 16.1% |
| Female householder, no spouse | 6,635 | 28.8% |
| Households with children under 18 | 8,548 | 37.1% |
| Households with seniors (65+) | 4,340 | 18.9% |
| Average household size | 2.68 | |
Marital status
| Status | Male | Female |
|---|---|---|
| Never married | 38.1% | 33.7% |
| Married | 50.0% | 43.7% |
| Separated | 2.0% | 2.9% |
| Widowed | 1.2% | 5.5% |
| Divorced | 8.6% | 14.1% |
Education
Less than 9th grade
4.9%
Some HS, no diploma
5.0%
HS graduate
22.9%
Some college, no degree
23.9%
Associate's degree
10.9%
Bachelor's degree
22.2%
Graduate / professional
10.2%
| Metric | % |
|---|---|
| HS diploma or higher | 90.1% |
| Bachelor's or higher | 32.4% |
School enrollment (ages 3–17)
| Type | Count | % |
|---|---|---|
| Nursery / preschool | 995 | 6.0% |
| Kindergarten | 1,112 | 6.7% |
| Elementary school | 5,800 | 35.1% |
| High school | 4,050 | 24.5% |
| College / grad school | 4,567 | 27.6% |
Employment
Industry of employment
Education & healthcare
18.6%
Professional & management
16.4%
Retail trade
12.9%
Arts, food & hospitality
10.7%
Manufacturing
9.8%
Construction
6.2%
Finance & real estate
6.2%
Other services
5.5%
Public administration
5.4%
Transportation & utilities
3.8%
Information
2.8%
Wholesale trade
1.6%
Agriculture & mining
0.2%
Occupation
| Category | % |
|---|---|
| Management, business & arts | 41.6% |
| Service | 15.2% |
| Sales & office | 24.1% |
| Natural resources & construction | 7.4% |
| Production & transportation | 11.7% |
Employment type
| Type | % |
|---|---|
| Private sector | 80.8% |
| Government | 14.1% |
| Self-employed | 5.0% |
| Unpaid family workers | 0.2% |
Commute
| Method | % |
|---|---|
| Drive alone | 69.3% |
| Carpool | 11.3% |
| Public transit | 0.1% |
| Walk | 1.3% |
| Work from home | 16.7% |
| Other means | 1.3% |
| Avg commute (minutes) | 24.2 |
Poverty
All people
10.1%
Under 18 years
16.5%
18 and over
8.2%
Married-couple families
2.8%
Female-led households
17.7%
Income support
| Source | % of households |
|---|---|
| Social Security | 17.7% |
| Retirement income | 18.2% |
| Supplemental Security | 3.2% |
| Cash public assistance | 1.2% |
| Food stamps / SNAP | 8.3% |
Health indicators
| Condition | % |
|---|---|
| Obesity | 33.1% |
| High blood pressure | 26.6% |
| High cholesterol | 29.5% |
| Diabetes | 8.7% |
| Heart disease | 3.9% |
| Stroke | 2.0% |
| Asthma | 8.9% |
| Arthritis | 17.6% |
| Kidney disease | 2.1% |
| Pulmonary disease | 4.3% |
| Cancer | 4.0% |
| Behavior / access | % |
|---|---|
| Smoking | 15.4% |
| Binge drinking | 21.2% |
| No physical activity | 21.2% |
| Less than 7 hrs sleep | 33.4% |
| Depression | 21.8% |
| Fair or poor health | 13.4% |
| Poor mental health | 15.3% |
| Poor physical health | 9.0% |
| No health insurance | 26.3% |
| Visited doctor (checkup) | 67.9% |
| Visited dentist | 58.3% |
| Cholesterol screening | 87.6% |
| Teeth loss | 12.2% |
Veterans & disability
| Veterans | Count | % |
|---|---|---|
| Civilian veterans | 3,501 | 7.4% |
| Disability | % |
|---|---|
| Any disability | 10.5% |
| Under 18 | 3.5% |
| 18–64 years | 8.8% |
| 65 and over | 39.8% |
Health insurance coverage
| Type | % |
|---|---|
| Private insurance | 72.2% |
| Public insurance | 22.9% |
| No insurance | 14.6% |
| Uninsured under 19 | 9.9% |
Language & origin
Language spoken at home (age 5+)
| Language | Count | % |
|---|---|---|
| English only | 58,505 | 94.1% |
| Spanish | 5,863 | 10.0% |
| Other Indo-European | 4,045 | 6.9% |
| Asian & Pacific Islander | 737 | 1.3% |
| Other languages | 451 | 0.8% |
Place of birth & citizenship
| Origin | Count | % |
|---|---|---|
| Native born (US) | 52,467 | 84.4% |
| Born in same state | 51,525 | 82.9% |
| Born in different state | 31,829 | 51.2% |
| Foreign born | 942 | 1.5% |
| Naturalized citizen | 9,701 | 15.6% |
| Not a US citizen | 4,536 | 46.8% |
Ancestry
| Ancestry | Count | % |
|---|---|---|
| French | 4,934 | 7.9% |
| Italian | 3,777 | 6.1% |
| Arab | 3,225 | 5.2% |
| English | 442 | 0.7% |
| Polish | 251 | 0.4% |
| Ancestry | Count | % |
|---|---|---|
| Dutch | 229 | 0.4% |
| Norwegian | 140 | 0.2% |
| German | 58 | 0.1% |
| Irish | 39 | 0.1% |
Technology access
| Metric | % of households |
|---|---|
| Computer access | 37.0% |
| Internet access | 99.1% |
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 78664
What part of Round Rock is ZIP code 78664?
ZIP code 78664 covers a portion of Round Rock, Texas, within Williamson County.
What county is ZIP code 78664 in?
ZIP code 78664 falls within Williamson County, Texas.
What is the population of ZIP code 78664?
ZIP code 78664 has an estimated population of 62,168 residents, with a density of 3,742 people per square mile.
What is the typical home value in ZIP code 78664?
The median home value in ZIP code 78664 is $281,800.
What is the median household income in ZIP code 78664?
The median household income in ZIP code 78664 is $83,599, above the national median of ~$75,000.
What timezone is ZIP code 78664 in?
ZIP code 78664 observes the CST timezone.