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Single Family ResidenceResidential
$1,083,458$575 / 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 Sep 24, 2026

643 S O ST

LIVERMORE, CA 94550
3
Beds
2
Baths
1,883 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.
0.17 ac
Lot SizeThe size of the land the home sits on, from county records.
1957
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
5
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.

Valuation

$1.1M
$1M low$1.2M high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$3,862 (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.$240,772 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$92,559
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$155,213
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$235,914
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$1,050,120

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountyALAMEDA
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.1958
Lot (acres)The size of the land the home sits on, from county records.0.17
ConstructionThe main material the home's frame and walls are built from.Wood (Unspecified)
RoofThe main material covering the roof, such as asphalt shingle or tile.Composition Shingle
HeatingThe type of heating system in the home.Forced Air With Air Conditioning
FireplaceWhether the home has a fireplace, and what kind.Yes
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(7)

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.

H
Granada High SchoolA
High · Grades 9–12 · 0.8 mi
E
Sunset Elementary SchoolA
Elementary · Grades KG–5 · 0.9 mi
M
William Mendenhall Middle SchoolB
Middle · Grades 6–8 · 1.4 mi

District: Livermore Valley Joint Unified School District

Neighborhood · ZIP 94550These 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.61
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 100.379

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.34%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.8%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.5%
PopulationHow many people live in this area.50,851
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.117 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$164,249
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$195,822
Average tempThe average temperature here across a full year.59°F
Annual precipHow much rain and melted snow falls here in a typical year.20 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.77%

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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

643 S O St 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 65% of homes in Livermore 94550
  • Costs less per square foot than 86% of homes in Livermore 94550
  • Bigger than 66% of homes in Alameda County
  • Has a bigger lot than 69% of homes in Alameda County
  • Older than 89% of homes in Livermore 94550

What homes are worth in Livermore 94550

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

This home
$386K$2.7M

This home is worth more than 35% of homes in Livermore 94550.

How it measures up in Livermore 94550

The dot is this home. The mark in the middle is the typical home in Livermore 94550.

Estimated value$1,083,458
CheaperTypical $1,209,763Pricier

Pricier than 35% of homes nearby

Price per ft²$575
CheaperTypical $664Pricier

Pricier than 14% of homes nearby

Living area1,883 ft²
SmallerTypical 1,825 ft²Bigger

Bigger than 52% of homes nearby

Lot size0.17 ac
SmallerTypical 0.18 acBigger

Bigger than 45% of homes nearby

Year built1957
OlderTypical 1972Newer

Newer than 11% of homes nearby

How 643 S O St ranks against every home in each area.
MeasureThis homeSouthside LivermoreLivermore 94550Alameda County
Estimated valuepricier than$1,083,45857% of homes35% of homes52% of homes
Price per ft²pricier than$57521% of homes14% of homes32% of homes
Living areabigger than1,883 ft²65% of homes52% of homes66% of homes
Lot sizebigger than0.17 ac64% of homes45% of homes69% of homes
Year builtnewer than195755% of homes11% of homes41% of homes

About 643 S O St

How much is 643 S O St, Livermore, CA worth?

The TopHap Estimate for 643 S O St, Livermore, CA is $1,083,458 as of Sep 24, 2026. The likely range is $1,013,989 to $1,152,927. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 643 S O St, Livermore, CA last sell?

643 S O St, Livermore, CA last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 643 S O St, Livermore, CA?

643 S O St, Livermore, CA has 3 bedrooms, 2 bathrooms, 1,883 square feet of living space and a 0.17-acre lot.

When was 643 S O St, Livermore, CA built?

643 S O St, Livermore, CA was built in 1957, making it 69 years old. The building has 2 stories.

What schools serve 643 S O St, Livermore, CA?

643 S O St, Livermore, CA is assigned to Granada High School (high), rated A; Sunset Elementary School (elementary), rated A; William Mendenhall Middle School (middle), rated B. All sit in Livermore Valley Joint Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 643 S O St, Livermore, CA compare to other homes in Livermore 94550?

Among the 16,034 homes in Livermore 94550, it is worth more than 35% of them ($1,083,458 against a typical $1,209,763), its price per square foot is higher than 14% of them ($575 against a typical $664), it is bigger than 52% of them (1,883 ft² against a typical 1,825 ft²), its lot is bigger than 45% of them (0.17 ac against a typical 0.18 ac) and it is newer than 11% of them (1957 against a typical 1972). Measured against all of Alameda County, it is worth more than 52% 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 643 S O St, Livermore, CA?

The 2025 property tax bill for 643 S O St, Livermore, CA was $3,862. The county assessed it at $240,772.

More homes on S O St

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Assigned schools

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