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Single Family ResidenceResidential
$542,520$223 / 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 94How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Oct 21, 2026
Last sold for $323,200 on Dec 6, 2018

621 KOLBO DR

ROUND ROCK, TX 78665
0
Baths
2,432 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.
0.25 ac
Lot SizeThe size of the land the home sits on, from county records.
2018
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

$543K
$508K low$577K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$323,200 · Dec 6, 2018

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$8,845 (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.$590,116 (2025)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$137,000
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$453,116
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$567,381
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$590,116

Climate Risk

Projected Flood DepthHow deep a serious flood is expected to get here at some point in the next 30 years. Shown in inches.9 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.6%
FEMA Flood ZoneFEMA's flood zone for this address. Zones starting with A or V are high risk, and lenders usually require flood insurance there.minimal

Scores 0–100; higher = greater projected risk.

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyWILLIAMSON
Lot (acres)The size of the land the home sits on, from county records.0.25
HeatingThe type of heating system in the home.Central
CoolingThe type of cooling or air conditioning in the home.Central
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.Porch · 413 ft²

Transaction History(1)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

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

M
Ridgeview Middle SchoolA
Middle · Grades 6–8 · 1.3 mi
E
Blackland Prairie Elementary SchoolA
Elementary · Grades KG–5 · 1.4 mi
H
Cedar Ridge High SchoolB
High · Grades 9–12 · 2.1 mi

District: Round Rock Independent School District

Neighborhood · ZIP 78665These 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.50
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.86
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.17

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.33%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.5.1%
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.68,549
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.3,056 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$112,722
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$135,285
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

621 Kolbo 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 91% of homes in Forest Grove
  • Costs more per square foot than 96% of homes in Round Rock 78665
  • Smaller than 96% of homes in Forest Grove
  • Has a bigger lot than 85% of homes in Round Rock 78665
  • Newer than 88% of homes in Forest Grove

What homes are worth in Round Rock 78665

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

This home
$275K$765K

This home is worth more than 85% of homes in Round Rock 78665.

How it measures up in Round Rock 78665

The dot is this home. The mark in the middle is the typical home in Round Rock 78665.

Estimated value$542,520
CheaperTypical $392,545Pricier

Pricier than 85% of homes nearby

Price per ft²$223
CheaperTypical $176Pricier

Pricier than 96% of homes nearby

Living area2,432 ft²
SmallerTypical 2,317 ft²Bigger

Bigger than 55% of homes nearby

Lot size0.25 ac
SmallerTypical 0.18 acBigger

Bigger than 85% of homes nearby

Year built2018
OlderTypical 2011Newer

Newer than 77% of homes nearby

How 621 Kolbo Dr ranks against every home in each area.
MeasureThis homeForest GroveRound Rock 78665Williamson County
Estimated valuepricier than$542,5209% of homes85% of homes78% of homes
Price per ft²pricier than$22386% of homes96% of homes75% of homes
Living areabigger than2,432 ft²4% of homes55% of homes65% of homes
Lot sizebigger than0.25 ac54% of homes85% of homes68% of homes
Year builtnewer than201888% of homes77% of homes75% of homes

About 621 Kolbo Dr

How much is 621 Kolbo Dr, Round Rock, TX worth?

The TopHap Estimate for 621 Kolbo Dr, Round Rock, TX is $542,520 as of Oct 21, 2026. The likely range is $507,913 to $577,127. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 621 Kolbo Dr, Round Rock, TX last sell?

621 Kolbo Dr, Round Rock, TX last sold on Dec 6, 2018 for $323,200, according to the county's recorded deed.

How big is 621 Kolbo Dr, Round Rock, TX?

621 Kolbo Dr, Round Rock, TX has 2,432 square feet of living space and a 0.25-acre lot.

When was 621 Kolbo Dr, Round Rock, TX built?

621 Kolbo Dr, Round Rock, TX was built in 2018, making it 8 years old. The building has 1 story.

What schools serve 621 Kolbo Dr, Round Rock, TX?

621 Kolbo Dr, Round Rock, TX is assigned to Ridgeview Middle School (middle), rated A; Blackland Prairie Elementary School (elementary), rated A; Cedar Ridge High School (high), rated B. All sit in Round Rock Independent School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 621 Kolbo Dr, Round Rock, TX compare to other homes in Round Rock 78665?

Among the 20,800 homes in Round Rock 78665, it is worth more than 85% of them ($542,520 against a typical $392,545), its price per square foot is higher than 96% of them ($223 against a typical $176), it is bigger than 55% of them (2,432 ft² against a typical 2,317 ft²), its lot is bigger than 85% of them (0.25 ac against a typical 0.18 ac) and it is newer than 77% of them (2018 against a typical 2011). Measured against all of Williamson County, it is worth more than 78% 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 621 Kolbo Dr, Round Rock, TX?

The 2025 property tax bill for 621 Kolbo Dr, Round Rock, TX was $8,845. The county assessed it at $590,116.

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