Zip lookup · TX

78666
San Marcos, Texas.

San Marcos, Hays County, TX · Austin-Round Rock-Georgetown, TX metro · population 88,583

What it costs per month · 78666 $1,624/mo

to buy the typical home at today's mortgage rate — +$714 (+79%) since Jan 2020.

What the home itself did
1 year
Down $9,382 -3%
$318,803$309,421 since Sep 2025
5 years
Down $23,513 -7%
$332,935$309,421 since Sep 2021

Monthly payment to buy the typical home

Home value × that month's 30-year mortgage rate, 20% down, principal and interest. This is the line households feel: prices and rates compound each other.

$500 $1,000 $1,500 $2,000 2002 2006 2010 2014 2018 2022 2026 78666 $1,624 United States $1,922
$500 $1,000 $1,500 $2,000 2002 2010 2018 2026
  • 78666$1,624
  • United States$1,922

At the last five years' pace, prices here aren't rising.

Typical home values in zip 78666 fell 2.9% over the past year — slower than the nation's +1.2%.

Asking rents in zip 78666 rose 0.8% over the past year — slower than the nation's +2.7%.

Owning the typical home in zip 78666 runs $949/mo more than renting one. The gap peaked at $1,396 in Oct 2022.

That is $2,367 a month against $1,418 rent: a $1,624 mortgage payment, plus $412 property tax and $331 insurance & upkeep.

Owning vs renting — zip 78666

The owning line is the typical home's monthly payment at that month's rate, plus property tax and insurance & upkeep; the renting line is the typical asking rent; the grey line is the mortgage payment on its own. Same homes, same months, both ways of paying for a roof.

$1,000 $2,000 $3,000 2018 2020 2022 2024 2026 Owning all in $2,367 Renting $1,418 Mortgage only $1,624
$1,000 $2,000 $3,000 2018 2022 2026
  • Owning all in$2,367
  • Renting$1,418
  • Mortgage only$1,624

Property tax · $412/mo 1.60% of value a year — the ACS 2020-2024 median bill over the median home value for 4 counties

Insurance & upkeep · $331/mo insurance, maintenance and repairs together, from the BLS Consumer Expenditure Survey — the national figure for mortgaged homeowners, scaled to this market's home value. BLS publishes the three bundled and they cannot be split.

Both are priced off the same month's home value, so they rise with the market. Neither is a quote — a specific home's bill depends on its assessment, its age and its insurer.

This zip spans 4 counties: Hays County, TX 78% · Guadalupe County, TX 16% · Comal County, TX 4% · Caldwell County, TX 2%

Zillow also publishes an index for the city itself: San Marcos, TX — measured over the city limits, which is a different area from this zip.

Asking rent $1,418 as of Sep 2026
+0.8%year on year
Typical home value $309,421 as of Sep 2026
-2.9%year on year

Asking rent — 78666

Against the Austin-Round Rock-Georgetown, TX metro and the national benchmark.

$1,200 $1,400 $1,600 $1,800 2018 2020 2022 2024 2026 78666 $1,418 Austin $1,603 United States $1,932
$1,200 $1,400 $1,600 $1,800 2018 2022 2026
  • 78666$1,418
  • Austin$1,603
  • United States$1,932

Typical home value — 78666

Mid-tier homes, smoothed and seasonally adjusted.

$200,000 $300,000 $400,000 $500,000 2018 2020 2022 2024 2026 78666 $309,421 Austin $414,273 United States $366,157
$200,000 $300,000 $400,000 $500,000 2018 2022 2026
  • 78666$309,421
  • Austin$414,273
  • United States$366,157

Within 20 miles

Miles sorted ascending, activate to sort descending Zip activate to sort by Zip City activate to sort by City Population activate to sort by Population Rent activate to sort by Rent Home value activate to sort by Home value
9.6 78655 Martindale 3,730 — $329,498
10.3 78656 Maxwell 2,847 $1,847 $252,451
12.2 78640 Kyle 77,531 $1,585 $293,532
14.1 78622 Fentress 331 — $227,154
14.2 78130 New Braunfels 104,009 $1,568 $301,994
15.0 78676 Wimberley 15,822 $2,099 $555,623
15.1 78132 New Braunfels 40,953 $1,586 $558,866
15.3 78623 Fischer 1,645 — $485,719
16.0 78610 Buda 48,319 $1,560 $358,454
16.0 78133 Canyon Lake 21,959 $1,738 $376,497
16.2 78619 Driftwood 6,693 $3,250 $925,971
17.8 78661 Prairie Lea 835 — $201,868
18.4 78644 Lockhart 22,348 $1,712 $277,573
18.8 78652 Manchaca 5,287 $2,499 $459,135
19.0 78638 Kingsbury 2,135 — $368,036
19.8 78123 McQueeney 2,127 — $431,996

Coordinates and population from SimpleMaps US Zips (Basic). Rent and home values from Zillow Research.