| Official Zip Code Name | Castell |
| Zip Code State | Texas |
| Primary County: | Llano |
| Area Code | 325 |
| Current Population: | 37081 |
| Racial Majority: | White 62.49% |
| Median Household Income | $55618 |
| Average Adjusted Gross Income | $89060 |
| Time Zone: | 6 |
| Elevation Range | 1200 ft. |
| Area | 8.209 Sqm. |
| Coordinates(Y,X) | 30.712760, -98.919033 |