ZIP code 78666
Where is ZIP code 78666?
San Marcos, Texas
Hays County · Standard ZIP code
ZIP code 78666 belongs to San Marcos, Texas in Hays County. 78666 is a standard ZIP code, so it covers street addresses as well as PO Boxes. It is in the Central Time zone and uses area codes 512, 737 and 830. About 88,583 people live in the 78666 area, where the median household income is $54,737. The closest ZIP codes are 78655 (Martindale, 5.9 mi southeast), 78656 (Maxwell, 7.7 mi east) and 78670 (Staples, 10.3 mi southeast).
| ZIP code | 78666 |
|---|---|
| Type | Standard ZIP code for street addresses and PO Boxes |
| Status | Active |
| City | San Marcos |
| State | Texas (TX) |
| County | Hays County |
| Time zone | Central Time · now |
| Area codes | 512, 737, 830 |
| Coordinates | 29.8754, -97.9404 map |
| 3-digit prefix | 786 |
Population and income in 78666
| Population | 88,583 · higher than 99% of Texas ZIP codes |
|---|---|
| People per square mile | 461 · higher than 66% of Texas ZIP codes |
| Median age | 26.9 years · lower than 95% of Texas ZIP codes |
| Men / women | 48% / 52% |
| Median household income | $54,737 · lower than 78% of Texas ZIP codes |
| Income per person | $29,465 |
| Below the poverty line | 24% |
| Bachelor’s degree or higher | 36% of adults 25+ |
| Median home value | $306,700 · higher than 75% of Texas ZIP codes |
| Median rent | $1,319 a month |
| Housing units | 36,580 |
| Households | 33,949 (2.36 people on average) |
| Owners / renters | 38% / 62% |
| Land area | 192.36 sq mi (plus 1.01 sq mi of water) |
Source: U.S. Census Bureau, American Community Survey 5-year estimates (2020–2024) for ZIP Code Tabulation Area 78666. Census ZIP areas are close to, but not exactly the same as, USPS delivery areas.
ZIP codes near 78666
| ZIP code | City | Distance | Type |
|---|---|---|---|
| 78655 | Martindale, TX | 5.9 mi SE | Standard |
| 78656 | Maxwell, TX | 7.7 mi E | Standard |
| 78670 | Staples, TX | 10.3 mi SE | PO Box only |
| 78640 | Kyle, TX | 10.5 mi NE | Standard |
| 78622 | Fentress, TX | 12.8 mi SE | PO Box only |
| 78667 | San Marcos, TX | 12.9 mi N | PO Box only |
| 78130 | New Braunfels, TX | 13.2 mi SW | Standard |
| 78676 | Wimberley, TX | 14.7 mi NW | Standard |
| 78638 | Kingsbury, TX | 15.5 mi SE | Standard |
| 78661 | Prairie Lea, TX | 15.7 mi SE | PO Box only |
| 78644 | Lockhart, TX | 15.8 mi E | Standard |
| 78610 | Buda, TX | 15.8 mi N | Standard |
Straight-line distance between ZIP code center points. Find every ZIP code within 10 miles of 78666 or measure the distance to another ZIP code.
How to address mail to 78666
123 MAIN ST
SAN MARCOS TX 78666
Put the city, the two-letter state code and the ZIP code on the last line. Adding the 4-digit ZIP+4 code (78666-XXXX) helps mail sort faster but isn’t required.
Other ZIP codes in San Marcos, TX
All San Marcos ZIP codes with population and income →
Questions
- What city is ZIP code 78666?
- 78666 is a San Marcos, Texas ZIP code.
- What county is 78666 in?
- ZIP code 78666 is in Hays County, Texas.
- What time zone is ZIP code 78666 in?
- 78666 is in the Central Time zone (America/Chicago).
- What area code is 78666?
- Phone numbers in ZIP code 78666 use area codes 512, 737 and 830.
- What is the population of ZIP code 78666?
- About 88,583 people live in ZIP code 78666, according to the Census Bureau’s American Community Survey (2020–2024).
- What is the median income in 78666?
- The median household income in 78666 is $54,737 a year, lower than 78% of Texas ZIP codes.
- What ZIP codes are near 78666?
- The nearest ZIP codes to 78666 are 78655 (Martindale, 5.9 miles), 78656 (Maxwell, 7.7 miles), 78670 (Staples, 10.3 miles) and 78640 (Kyle, 10.5 miles).