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Single Family ResidenceResidential
$1,142,348$415 / 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

121 W 4TH ST

SAN DIMAS, CA 91773
4
Beds
2
Baths
2,750 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.
0.16 ac
Lot SizeThe size of the land the home sits on, from county records.
1911
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.
11
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.

Valuation

$1.1M
$1.1M low$1.2M high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$2,901 (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.$178,500 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$23,181
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$155,319
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$175,001

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
StyleThe architectural style of the home, such as ranch or colonial.Conventional
CountyLOS ANGELES
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.1925
Lot (acres)The size of the land the home sits on, from county records.0.16
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.Floor/Wall Furnace
PoolWhether the property has a pool, and what kind, such as in-ground.No

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

E
Fred Ekstrand Elementary SchoolA-
Elementary · Grades KG–5 · 0.3 mi
H
San Dimas High SchoolA-
High · Grades 9–12 · 1.2 mi
M
Lone Hill Middle SchoolA-
Middle · Grades 6–8 · 1.5 mi

District: Bonita Unified School District

Neighborhood · ZIP 91773These 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.68
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.103
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.549

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.8.3%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.7%
PopulationHow many people live in this area.33,478
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.2,155 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$100,808
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$124,896
Average tempThe average temperature here across a full year.63°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.73%

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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

121 W 4th 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 78% of homes in San Dimas 91773
  • Costs less per square foot than 91% of homes in San Dimas 91773
  • Bigger than 90% of homes in San Dimas 91773
  • Has a smaller lot than 74% of homes in San Dimas 91773
  • Older than 98% of homes in San Dimas 91773

What homes are worth in San Dimas 91773

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

This home
$517K$2M

This home is worth more than 78% of homes in San Dimas 91773.

How it measures up in San Dimas 91773

The dot is this home. The mark in the middle is the typical home in San Dimas 91773.

Estimated value$1,142,348
CheaperTypical $890,099Pricier

Pricier than 78% of homes nearby

Price per ft²$415
CheaperTypical $519Pricier

Pricier than 9% of homes nearby

Living area2,750 ft²
SmallerTypical 1,674 ft²Bigger

Bigger than 90% of homes nearby

Lot size0.16 ac
SmallerTypical 0.19 acBigger

Bigger than 26% of homes nearby

Year built1911
OlderTypical 1977Newer

Newer than 2% of homes nearby

How 121 W 4th St ranks against every home in each area.
MeasureThis homeSan Dimas 91773Los Angeles County
Estimated valuepricier than$1,142,34878% of homes72% of homes
Price per ft²pricier than$4159% of homes14% of homes
Living areabigger than2,750 ft²90% of homes86% of homes
Lot sizebigger than0.16 ac26% of homes47% of homes
Year builtnewer than19112% of homes2% of homes

About 121 W 4th St

How much is 121 W 4th St, San Dimas, CA worth?

The TopHap Estimate for 121 W 4th St, San Dimas, CA is $1,142,348 as of Oct 21, 2026. The likely range is $1,073,865 to $1,210,831. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 121 W 4th St, San Dimas, CA last sell?

121 W 4th St, San Dimas, CA last sold on Jan 1, 1900, according to the county's recorded deed.

How big is 121 W 4th St, San Dimas, CA?

121 W 4th St, San Dimas, CA has 4 bedrooms, 2 bathrooms, 2,750 square feet of living space and a 0.16-acre lot.

When was 121 W 4th St, San Dimas, CA built?

121 W 4th St, San Dimas, CA was built in 1911, making it 115 years old. It is a conventional home. The building has 2 stories.

What schools serve 121 W 4th St, San Dimas, CA?

121 W 4th St, San Dimas, CA is assigned to Fred Ekstrand Elementary School (elementary), rated A-; San Dimas High School (high), rated A-; Lone Hill Middle School (middle), rated A-. All sit in Bonita Unified School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 121 W 4th St, San Dimas, CA compare to other homes in San Dimas 91773?

Among the 10,111 homes in San Dimas 91773, it is worth more than 78% of them ($1,142,348 against a typical $890,099), its price per square foot is higher than 9% of them ($415 against a typical $519), it is bigger than 90% of them (2,750 ft² against a typical 1,674 ft²), its lot is bigger than 26% of them (0.16 ac against a typical 0.19 ac) and it is newer than 2% of them (1911 against a typical 1977). Measured against all of Los Angeles County, it is worth more than 72% 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 121 W 4th St, San Dimas, CA?

The 2025 property tax bill for 121 W 4th St, San Dimas, CA was $2,901. The county assessed it at $178,500.

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