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Single Family ResidenceResidential
$1,116,257$484 / 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 92How 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

16645 COWELL ST

CASTRO VALLEY, CA 94578
0
Baths
2,308 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.
3,942 ft²
Lot SizeThe size of the land the home sits on, from county records.
1976
Year BuiltThe year the home was originally built, according to county records.

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.$3,305 (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.$210,708 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$64,876
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$152,832
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$206,440
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$1,305,180

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.1978
Lot (acres)The size of the land the home sits on, from county records.0.09
ConstructionThe main material the home's frame and walls are built from.Wood (Unspecified)
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(6)

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.

E
Stanton Elementary SchoolB-
Elementary · Grades KG–5 · 0.3 mi
H
Castro Valley High SchoolA
High · Grades 9–12 · 1.3 mi
M
Creekside Middle SchoolA+
Middle · Grades 6–8 · 2.2 mi

District: Castro Valley Unified School District

Neighborhood · ZIP 94578These 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.96
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.90
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.654

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.21%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.13%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.3%
PopulationHow many people live in this area.36,127
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.9,333 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$79,481
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$101,965
Average tempThe average temperature here across a full year.58°F
Annual precipHow much rain and melted snow falls here in a typical year.21 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.78%

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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

16645 Cowell 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 more than 98% of homes in San Leandro 94578
  • Costs less per square foot than 90% of homes in Castro Valley
  • Bigger than 92% of homes in San Leandro 94578
  • Has a smaller lot than 92% of homes in Castro Valley
  • Newer than 78% of homes in San Leandro 94578

What homes are worth in San Leandro 94578

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

This home
$331K$1.2M

This home is worth more than 98% of homes in San Leandro 94578.

How it measures up in San Leandro 94578

The dot is this home. The mark in the middle is the typical home in San Leandro 94578.

Estimated value$1,116,257
CheaperTypical $728,554Pricier

Pricier than 98% of homes nearby

Price per ft²$484
CheaperTypical $540Pricier

Pricier than 29% of homes nearby

Living area2,308 ft²
SmallerTypical 1,344 ft²Bigger

Bigger than 92% of homes nearby

Lot size3,942 ft²
SmallerTypical 0.13 acBigger

Bigger than 9% of homes nearby

Year built1976
OlderTypical 1953Newer

Newer than 78% of homes nearby

How 16645 Cowell St ranks against every home in each area.
MeasureThis homeCastro ValleySan Leandro 94578Alameda County
Estimated valuepricier than$1,116,25755% of homes98% of homes54% of homes
Price per ft²pricier than$48410% of homes29% of homes16% of homes
Living areabigger than2,308 ft²79% of homes92% of homes81% of homes
Lot sizebigger than3,942 ft²8% of homes9% of homes18% of homes
Year builtnewer than197667% of homes78% of homes65% of homes

About 16645 Cowell St

How much is 16645 Cowell St, Castro Valley, CA worth?

The TopHap Estimate for 16645 Cowell St, Castro Valley, CA is $1,116,257 as of Sep 24, 2026. The likely range is $1,029,159 to $1,203,355. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 16645 Cowell St, Castro Valley, CA last sell?

16645 Cowell St, Castro Valley, CA last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 16645 Cowell St, Castro Valley, CA?

16645 Cowell St, Castro Valley, CA has 2,308 square feet of living space and a 0.09-acre lot.

When was 16645 Cowell St, Castro Valley, CA built?

16645 Cowell St, Castro Valley, CA was built in 1976, making it 50 years old.

What schools serve 16645 Cowell St, Castro Valley, CA?

16645 Cowell St, Castro Valley, CA is assigned to Stanton Elementary School (elementary), rated B-; Castro Valley High School (high), rated A; Creekside Middle School (middle), rated A+. All sit in Castro Valley Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 16645 Cowell St, Castro Valley, CA compare to other homes in San Leandro 94578?

Among the 7,904 homes in San Leandro 94578, it is worth more than 98% of them ($1,116,257 against a typical $728,554), its price per square foot is higher than 29% of them ($484 against a typical $540), it is bigger than 92% of them (2,308 ft² against a typical 1,344 ft²), its lot is bigger than 9% of them (3,942 ft² against a typical 0.13 ac) and it is newer than 78% of them (1976 against a typical 1953). Measured against all of Alameda County, it is worth more than 54% 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 16645 Cowell St, Castro Valley, CA?

The 2025 property tax bill for 16645 Cowell St, Castro Valley, CA was $3,305. The county assessed it at $210,708.

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Assigned schools

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