Residential delivery area · Texas
ZIP Code 78664: Round Rock, TX
ZIP code 78664 is in Round Rock, Texas, mostly in Williamson County (86% of its land) with the rest in Travis County (Census 2020 ZIP-county file). About 62,000 people live there (Census Bureau, ACS 2020-2024), the 2nd most populous of Round Rock's 3 residential ZIP codes. Median household income is $87,417 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Round Rock (72%) and Pflugerville (10%); 19% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Round Rock · 3 residential ZIPs
- County
- Williamson County (86%); Travis County (14%)
- Census places
- Round Rock (72%); Pflugerville (10%)
- Metro area
- Austin-Round Rock-San Marcos, TX
- House districts
- TX-17 (89%), TX-31 (11%) 119th Congress, by share of land
- State
- Texas
- Time zone
- Central
- Land area
- 16.6 sq mi · 3,736 people per sq mi
Where is ZIP code 78664?
78664 centers on 30.505°, -97.647° and covers 16.6 square miles of land plus 0.1 of water. It borders 5 ZIP codes: 78665, 78728, 78681, 78660, 78634.
The map draws ZIP code areas only. For the streets inside 78664, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 78664 compare with the rest of Round Rock?
| Measure | 78664 | In Round Rock | In Williamson County | In TX |
|---|---|---|---|---|
| People (ACS 2020-2024) | 62,060 | 2nd of 3 | 4th of 27 | 72nd of 1,990 |
| Median household income | $87k | 3rd of 3 | 17th of 22 | 343rd of 1,172 |
| Median home value | $358k | 3rd of 3 | 17th of 24 | 262nd of 1,172 |
Its median household income is higher than in 71% of U.S. residential ZIP codes, and it is denser than 91% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 78664?
The 2020 Census counted 60,287 people in 78664; the ACS, which samples households over 2020-2024, estimates 62,060. Between the 2010 and 2020 censuses its population grew 13.9% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 62,060
- 2020 Census count
- 60,287+13.9% since 2010 (52,932)
- Households
- 23,484
- Median age
- 35.1
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 78664?
Of the 62,060 people the ACS estimates in 78664, 22.3% are under 18 and 10.8% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (39.6%), then Hispanic or Latino (35.8%).
- Under 1822.3%
- 18 to 6466.9%
- 65 and older10.8%
- White, not Hispanic39.6%
- Hispanic or Latino35.8%
- Black, not Hispanic13.7%
- Asian, not Hispanic5.8%
- Other or two or more5.1%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 78664 earn?
Median household income is $87,417 (ACS 2020-2024), the 17th highest of the 22 ranked ZIP codes in Williamson County. It is not measurably different from 2015-2019 ($92,964 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $87,417
- Income per person
- $43,876
- Below the poverty line
- 10.2%
- Unemployed (of the labor force)
- 4.4%
- Adults 25+ with a bachelor's degree
- 36.4%
- Adjusted gross income per tax return, 2022
- $79,23427,970 returns; wages 81% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 78664?
FHFA's house price index for 78664, built from repeat sales and appraisals of the same homes, rose 106% from 2015 to 2025 and rose 44% from 2020 to 2025, and moved −0.1% in 2025.
- Median home value (owners' estimate)
- $358,200
- Median gross rent
- $1,692
- Homes owned by their occupants
- 53.7%
- Housing units
- 24,497
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 78664?
1,841 business establishments had a location in this ZIP code in 2023, 293 more than in 2018; the most are in retail trade (ZIP Code Business Patterns).
- Retail trade284
- Professional, scientific, and technical services264
- Health care and social assistance202
- Accommodation and food services188
- Construction176
- Other services (except public administration)157
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 78664?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 78665 | Round Rock | 66,171 | $123k | 3.1 mi |
| 78728 | Austin | 26,777 | $75k | 4.3 mi |
| 78681 | Round Rock | 56,691 | $138k | 4.8 mi |
| 78660 | Pflugerville | 124,834 | $113k | 5.5 mi |
| 78634 | Hutto | 46,413 | $114k | 7.2 mi |
| 78717 | Austin | 37,262 | $145k | 6.4 mi (near) |
| 78727 | Austin | 29,958 | $110k | 6.7 mi (near) |
| 78729 | Austin | 30,460 | $86k | 7.3 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.