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Single Family ResidenceResidential
$323,188$214 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 96How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Aug 30, 2026

503 KAROLYN DR

ROUND ROCK, TX 78664
2
Baths
1,511 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
0.36 ac
Lot SizeThe size of the land the home sits on, from county records.
1971
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$323K
$309K low$337K high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$1,973 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$328,198 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$69,500
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$258,698
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$338,168
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$328,198

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyWILLIAMSON
Effective Year BuiltAn adjusted build year that accounts for condition and major remodels. A big renovation can make a home count as newer than it is.1987
Lot (acres)The size of the land the home sits on, from county records.0.36
HeatingThe type of heating system in the home.Central
CoolingThe type of cooling or air conditioning in the home.Central
FireplaceWhether the home has a fireplace, and what kind.Yes
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Deck · 162 ft²Patio · 104 ft²Porch · 218 ft²

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Robertson Elementary SchoolC
Elementary · Grades PK–5 · 0.8 mi
M
Hernandez Middle SchoolC+
Middle · Grades 6–8 · 0.9 mi
H
Stony Point High SchoolC+
High · Grades 9–12 · 1.1 mi

District: Round Rock Independent School District

Neighborhood · ZIP 78664These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.87
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.87
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.13

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.96%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.24%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.8.6%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.4%
PopulationHow many people live in this area.72,016
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.4,336 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$88,209
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$105,122
Average tempThe average temperature here across a full year.67°F
Annual precipHow much rain and melted snow falls here in a typical year.35 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.60%

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Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

503 Karolyn Dr measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Worth less than 76% of homes in Williamson County
  • Costs more per square foot than 70% of homes in Round Rock 78664
  • Smaller than 82% of homes in Williamson County
  • Has a bigger lot than 89% of homes in Round Rock 78664
  • Older than 97% of homes in Williamson County

What homes are worth in Round Rock 78664

Each bar is how many homes fall in that price range. The marker is this home.

This home
$228K$872K

This home is worth more than 45% of homes in Round Rock 78664.

How it measures up in Round Rock 78664

The dot is this home. The mark in the middle is the typical home in Round Rock 78664.

Estimated value$323,188
CheaperTypical $331,138Pricier

Pricier than 45% of homes nearby

Price per ft²$214
CheaperTypical $197Pricier

Pricier than 70% of homes nearby

Living area1,511 ft²
SmallerTypical 1,761 ft²Bigger

Bigger than 33% of homes nearby

Lot size0.36 ac
SmallerTypical 0.18 acBigger

Bigger than 89% of homes nearby

Year built1971
OlderTypical 1998Newer

Newer than 4% of homes nearby

How 503 Karolyn Dr ranks against every home in each area.
MeasureThis homeRound Rock 78664Williamson County
Estimated valuepricier than$323,18845% of homes24% of homes
Price per ft²pricier than$21470% of homes64% of homes
Living areabigger than1,511 ft²33% of homes18% of homes
Lot sizebigger than0.36 ac89% of homes78% of homes
Year builtnewer than19714% of homes3% of homes

About 503 Karolyn Dr

How much is 503 Karolyn Dr, Round Rock, TX worth?

The TopHap Estimate for 503 Karolyn Dr, Round Rock, TX is $323,188 as of Aug 30, 2026. The likely range is $309,406 to $336,970. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 503 Karolyn Dr, Round Rock, TX last sell?

503 Karolyn Dr, Round Rock, TX last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 503 Karolyn Dr, Round Rock, TX?

503 Karolyn Dr, Round Rock, TX has 2 bathrooms, 1,511 square feet of living space and a 0.36-acre lot.

When was 503 Karolyn Dr, Round Rock, TX built?

503 Karolyn Dr, Round Rock, TX was built in 1971, making it 55 years old. The building has 1 story.

What schools serve 503 Karolyn Dr, Round Rock, TX?

503 Karolyn Dr, Round Rock, TX is assigned to Robertson Elementary School (elementary), rated C; Hernandez Middle School (middle), rated C+; Stony Point High School (high), rated C+. All sit in Round Rock Independent School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 503 Karolyn Dr, Round Rock, TX compare to other homes in Round Rock 78664?

Among the 16,951 homes in Round Rock 78664, it is worth more than 45% of them ($323,188 against a typical $331,138), its price per square foot is higher than 70% of them ($214 against a typical $197), it is bigger than 33% of them (1,511 ft² against a typical 1,761 ft²), its lot is bigger than 89% of them (0.36 ac against a typical 0.18 ac) and it is newer than 4% of them (1971 against a typical 1998). Measured against all of Williamson County, it is worth more than 24% of homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 503 Karolyn Dr, Round Rock, TX?

The 2025 property tax bill for 503 Karolyn Dr, Round Rock, TX was $1,973. The county assessed it at $328,198.

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