ZIP Code Tabulation Area · Texas

ZIP Code 78665: Round Rock, TX

ZIP Code 78665 (Round Rock, Williamson County, Texas) has an estimated 66,171 residents in 24,162 households. The median household income is $122,680, the median home value is $474,100 and the median gross rent is $1,938/mo. Figures are U.S. Census Bureau American Community Survey 2020–2024 5-year estimates for the matching ZIP Code Tabulation Area.

American Community Survey 2020–2024 5-year estimates · Updated Oct 26, 2026

Total population

66,171

Margin of error ±3,343

Median household income

$122,680

Margin of error ±$7,223

Median home value

$474,100

Margin of error ±$9,632

Median gross rent

$1,938/mo

Margin of error ±$69

Median age

35.5 yrs

Margin of error ±0.8 yrs

Mean travel time to work

27.8 min

Margin of error ±2.4 min

How ZIP 78665 compares with Texas and the U.S.

State and national figures are the Census Bureau's own estimates for those areas from the same ACS release, not averages of ZIP codes.

Median age

ZIP 7866535.5 yrsTexas35.6 yrsUnited States38.9 yrs

Median household income

ZIP 78665$122,680Texas$78,476United States$80,734

Per capita income

ZIP 78665$56,191Texas$40,752United States$44,673

Poverty rate

ZIP 786654.7%Texas13.8%United States12.5%

Unemployment rate

ZIP 786653.4%Texas5.3%United States5.2%

Bachelor's degree or higher

ZIP 7866553.6%Texas33.8%United States35.7%

Median home value

ZIP 78665$474,100Texas$283,800United States$332,700

Median gross rent

ZIP 78665$1,938/moTexas$1,403/moUnited States$1,413/mo

Owner-occupied homes

ZIP 7866561.4%Texas62.6%United States65.2%

Mean travel time to work

ZIP 7866527.8 minTexas26.7 minUnited States26.4 min

Worked from home

ZIP 7866527.0%Texas14.4%United States15.1%

All figures for ZIP 78665

Each estimate has a 90% margin of error: the true value is likely within that range. * marks estimates with a large margin of error (a coefficient of variation above 30%, or ±10 percentage points or more for rates).

ZIP 78665 — ACS 2020–2024 5-year estimates
Measure	ZIP 78665	Margin of error	Texas	United States
Total population	66,171	±3,343	30,188,424	334,922,499
Median age	35.5 yrs	±0.8 yrs	35.6 yrs	38.9 yrs
Households	24,162	±1,047	10,992,816	129,227,496
Median household income	$122,680	±$7,223	$78,476	$80,734
Per capita income	$56,191	±$3,364	$40,752	$44,673
Poverty rate	4.7%	±1.1 pts	13.8%	12.5%
Unemployment rate	3.4%	±0.8 pts	5.3%	5.2%
Bachelor's degree or higher	53.6%	±2.6 pts	33.8%	35.7%
Median home value	$474,100	±$9,632	$283,800	$332,700
Median gross rent	$1,938/mo	±$69	$1,403/mo	$1,413/mo
Owner-occupied homes	61.4%	±2.4 pts	62.6%	65.2%
Mean travel time to work	27.8 min	±2.4 min	26.7 min	26.4 min
Worked from home	27.0%	±2.6 pts	14.4%	15.1%

Race and Hispanic or Latino origin

Shares of the total population by the Census Bureau's race and Hispanic or Latino origin categories (table B03002), listed in the Census Bureau's order. People self-identify on the survey.

Population by race and Hispanic or Latino origin, ZIP 78665
Group	ZIP 78665	Texas	United States
White alone, not Hispanic or Latino	45.4%	39.1%	57.4%
Black or African American alone, not Hispanic or Latino	11.5%	11.9%	11.9%
American Indian and Alaska Native alone, not Hispanic or Latino	0.1%	0.1%	0.5%
Asian alone, not Hispanic or Latino	11.5%	5.5%	5.9%
Native Hawaiian and Other Pacific Islander alone, not Hispanic or Latino	0.5%	0.1%	0.2%
Some other race alone, not Hispanic or Latino	0.8%	0.4%	0.6%
Two or more races, not Hispanic or Latino	6.1%	3.1%	4.3%
Hispanic or Latino (of any race)	24.3%	39.7%	19.3%

Where ZIP 78665 is

State: Texas
Main county: Williamson County
Largest overlapping place: Round Rock (61% of the ZIP's land area)
Land area: 24.08 sq mi· about 2,748 people per sq mi

County and place names come from the Census Bureau's 2020 ZCTA relationship files. A ZIP code's mailing city, set by the U.S. Postal Service, can differ from these names.

Other ZIP codes in Williamson County

76527 Williamson County, TX 76530 Williamson County, TX 76537 Williamson County, TX 76574 Williamson County, TX 76578 Williamson County, TX 78613 Cedar Park, TX 78615 Williamson County, TX 78626 Georgetown, TX 78628 Georgetown, TX 78633 Georgetown, TX 78634 Hutto, TX 78642 Williamson County, TX 78664 Round Rock, TX 78674 Weir, TX 78681 Round Rock, TX 78717 Austin, TX 78729 Austin, TX

See every ZIP code in Texas, or compare ZIP 78665 with another ZIP code.

Census figures describe residents as a group and cannot tell you about any one home or street. For a specific address, check local government and housing records.

About ZIP codes and ZCTAs: the Census Bureau publishes statistics for ZIP Code Tabulation Areas, which approximate USPS ZIP code delivery areas. Learn how they differ.

Sources

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, detailed tables B01003, B01002, B11001, B19013, B19301, B17001, B23025, B15003, B25077, B25064, B25003, B08013, B08303, B08301, B03002 — snapshot Oct 26, 2026.
U.S. Census Bureau, 2020 ZCTA5 relationship files (county and place).
Data: U.S. Census Bureau, American Community Survey 5-year estimates (detailed tables) and 2020 Census ZCTA relationship files. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau. These agencies do not endorse OpenZIP.