Williamson County · Texas
ZIP code 78665
- Population
- 64,087
- Median income
- $117,240
- Median home
- $438,700
- Sales tax
- 6.25%
ZCTA residents
Household, past 12 months
Owner-occupied value
Texas state rate
Quick answer
ZIP 78665 sits in Williamson County, Texas and is home to 64,087 people. Median household income is $117,240, the median home is worth $438,700 and median gross rent is $1,945. 63.8% of households own their home, and purchases are taxed at 6.25% (Texas state rate).
- County
- Williamson County
- State
- Texas (TX)
- Area codes
- Not published
- Metro area
- Outside covered metros
FIPS 48491
1,989 ZIPs covered
No NANPA match for this ZIP
Rate jurisdiction used for tax
The numbers for 78665
American Community Survey 2019-2023 ACS 5-year estimates for this ZCTA.
- Population
- 64,087ZIP 78665 residents
- Median household income
- $117,240Past 12 months, inflation adjusted
- Median home value
- $438,700Owner-occupied units
- Median gross rent
- $1,945Rent plus utilities, monthly
- Median age
- 36.1 yrsAll residents
- Homeownership rate
- 63.8%Owner-occupied households
Sales tax in 78665
What a purchase inside this ZIP costs at checkout.
Texas levies 6.25% statewide, and counties, cities and special districts inside this ZIP can add their own local rate on top. Check the county page for the local component before you quote a price.
Affordability in this ZIP
Derived from the Census medians above — indicative, not an offer.
A rent burden above 30% is the federal threshold for cost-burdened households, and a price-to-income multiple above 4× is generally considered a stretched housing market. The mortgage figure is principal and interest only — taxes, insurance and HOA dues are extra.
How 78665 compares
ZIP 78665 against the median ZIP in Williamson County and across Texas.
| Measure | ZIP 78665 | County median | State median | vs state |
|---|---|---|---|---|
| Median household income | $117,240 | $101,250 | $68,103 | +72% |
| Median home value | $438,700 | $364,450 | $194,900 | +125% |
| Median gross rent | $1,945 | $1,687 | $1,105 | +76% |
| Population | 64,087 | 28,877 | 5,317 | +1105% |
Medians are computed across the 19 ZIP areas in Williamson County and the 1989 ZIP areas in Texas.
Statewide rank
Where this ZIP places among all 1989 Texas ZIP areas.
- Income
- #132
- Home value
- #144
- Population
- #60
richer than 92% of 1,756 state ZIPs
above 92% of 1,705 state ZIPs
larger than 97% of 1,989 state ZIPs
Comparable ZIP codes
Texas ZIP areas with almost the same household income.
Nearby ZIP codes
Other ZIP codes filed under Williamson County.
ZIP 78665 questions
Common questions about this ZIP code.
- Where is ZIP code 78665?
- ZIP 78665 lies mostly in Williamson County, Texas. County assignment follows the largest share of land area, so a ZIP straddling a county line is filed under its dominant county.
- What sales tax do I pay in 78665?
- Texas charges 6.25% statewide, plus any county, city or district rate that applies locally.
- Is 78665 expensive to live in?
- Median rent runs $1,945 a month, about 20% of median household income, and the median home is worth $438,700 — +125% against the typical Texas ZIP.
- Is a ZCTA the same as a postal ZIP code?
- Not exactly. The Census builds ZIP Code Tabulation Areas from the ZIP codes of addresses inside each census block, so a ZCTA can differ slightly from the USPS delivery route of the same number, and PO-box-only ZIPs have no ZCTA at all.
Keep going
Related pages for this area.
Sources & transparency
- US Census Bureau, ACS 2019-2023 5-year estimates — 2019-2023 ACS 5-year — population, income, housing
- Census 2020 ZCTA-to-county relationship file — County assignment by largest land-area overlap
- Texas Comptroller of Public Accounts — Sales tax rates and local add-ons
Last reviewed December 2024. Figures are published for reference and can change; verify with the source agency before filing or contracting. How we build and check this data.