| City: | Castell, Texas |
| Counties: | Llano County[Primary] Mason County |
| Timezone: | Central (GMT -06:00) |
| Local Time: | 9:38:30 AM |
| Population: | 31 [See All] |
| Area Code: | 325 |
| Classification: | Standard [Normal Street Delivery] |
| Coordinates: | 30.7670, -98.9543 |
| Land Area: | 8.209 sq mi |
| Quick Link: |
ZIP Code 76831 has 31 residents and 19 households (average 1.63 persons per household). The median age is 66.3 years, significantly older than the state (35.6) and significantly older than the nation (38.8). The gender split is 19.4% male and 80.6% female, which is much lower than the state male share (49.4%), making this a female-majority area. Largest groups are White (87.1%, much higher than the state average of 50.1% and well above the national average of 61.6%) and Hispanic or Latino (9.7%); Hispanic or Latino residents make up 9.7%, which is much lower than the state average (39.3%).
Explore More:Population Over TimeBy Age & GenderBy RaceBy GenderNativity & Citizenship
| 2020 Population: | 31Source: Census DHC |
| 2024 ACS Population Estimate: | 0Source: Census ACS |
| 2026 ZC Population Estimate: | 19Source: ZIP-Codes.com |
| Population Density: | 3.8 people per sq mile |
| Average Income: | $0Source: Census ACS |
| Households: | 19Source: Census DHC |
| Average House Value: | $666,666,666Source: Census ACS |
| Persons Per Household: | 1.63Source: Census DHC |
| Average Family Size: | 3.50Source: Census ACS |
| Group | 2010 | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Census ACS Population Estimate | -- | 38 | 83 | 74 | 82 | 81 | 102 | 39 | 36 | 0 | 0 | 0 | 0 | 0 | 0 |
| Decennial Census | 63 | -- | -- | -- | -- | -- | -- | -- | -- | -- | 31 | -- | -- | -- | -- |
Median Age: 66.3
Male Median Age: 60.5
Female Median Age: 66.8
| Group | < 5 | 5-9 | 10-14 | 15-19 | 20-24 | 25-29 | 30-34 | 35-39 | 40-44 | 45-49 | 50-54 | 55-59 | 60-64 | 65-69 | 70-74 | 75-79 | 80-84 | 85+ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Male | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 1 | 1 | 0 | 2 | 0 | 0 | 0 |
| Female | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 3 | 1 | 0 | 1 | 5 | 4 | 7 | 0 | 0 |
| Total | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 3 | 3 | 1 | 2 | 5 | 6 | 7 | 0 | 0 |
| White: | 27 | 90.00% |
| Black: | 0 | 0% |
| Hispanic:* | 3 | 10.00% |
| Asian: | 0 | 0% |
| American Indian: | 0 | 0% |
| Hawaiian: | 0 | 0% |
| Other: | 0 | 0% |
| Total: | 30 | 100% |
| Gender | Count | % | Median Age |
|---|---|---|---|
| Males: | 6 | 19.35% | 60.5 years |
| Females: | 25 | 80.65% | 66.8 years |
| Total: | 31 | 100% | 66.3 years |
| Native, born in the United States: | 0 | 0% |
| Native, born in PR, Island Areas, or abroad: | 0 | 0% |
| Foreign born, naturalized U.S. citizen: | 0 | 0% |
| Foreign born, not a U.S. citizen: | 0 | 0% |
| Total Population: | 0 | 100% |
| Total Native Population: | 0 | 0% |
| Total Foreign-born Population: | 0 | 0% |
ZIP Code 76831 supports both business and residential activity. According to the Business Census (2024), there are 4 business establishments, employing about 11 people with an annual payroll of $496,000. USPS data shows 12 residential mailboxes and 0 business mailboxes, reflecting local delivery coverage.
| # Residential Mailboxes: | 12Source: USPS |
| # Business Mailboxes: | 0Source: USPS |
| Total Delivery Receptacles: | 67Source: USPS |
| Single Family Delivery Units: | 12Source: USPS |
| Multi Family Delivery Units: | 0Source: USPS |
| # of Businesses: | 4Source: CBP |
| 1st Quarter Payroll: | $107,000Source: CBP |
| Annual Payroll: | $496,000Source: CBP |
| # of Employees: | 11Source: CBP |
ZIP Code 76831 is located in Llano County, Texas, within the Metropolitan Statistical Area (CBSA ) and Texas's 11st Congressional District. This area has a population of 0 people, about 0.00% of whom live in ZIP Code 76831. It covers 8.209 sq mi of land and a water area of 0.016 sq mi.
| CBSA Name: | --Source: Census |
| CBSA Number: | --Source: Census |
| CBSA Type: | --Source: Census |
| CBSA Division: | --Source: Census |
| CBSA Population: | 0Source: Census |
| MSA: | Source: Census |
| Land Area: | 8.209 sq miSource: Census |
| Water Area: | 0.016 sq miSource: Census |
| Congressional District: | 11Source: USPS |
| Congressional Land Area: | 27832.17 sq miSource: Census |
| PMSA: | Source: Census |
| Intro Date: | < 2004-10Source: ZIP-Codes.com |
| Place FIPS Code: | --Source: Census |
| Place Name: | --Source: Census |
We could not locate which school district 76831 belongs to, but we will update this once new district data is released. There are no public schools nor private schools with a mailing address in this ZIP Code. Listing Nearby schools instead. It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.
Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on March 1, 2026.