Skip to content
Skip to content
TopHapOpen in map
Single Family ResidenceResidential
$2,511,152$1,486 / 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
Last sold for $2,500,000 on Jun 8, 2021

421 SONORA DR

SAN MATEO, CA 94402
3
Beds
2
Baths
1,690 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.
0.14 ac
Lot SizeThe size of the land the home sits on, from county records.
1939
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
7
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
1
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$2.5M
$2.3M low$2.7M high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$2,500,000 · Jun 8, 2021

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$30,094 (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.$2,550,000 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$1,785,000
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$765,000
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$2,601,000
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$2,343,960

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
CountySAN MATEO
Lot (acres)The size of the land the home sits on, from county records.0.14
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

Transaction History(4)

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
Baywood Elementary SchoolA-
Elementary · Grades KG–5 · 0.2 mi
H
Aragon High SchoolA+
High · Grades 9–12 · 0.2 mi
M
Borel Middle SchoolA-
Middle · Grades 6–8 · 0.4 mi

District: San Mateo-Foster City Elementary School District

Neighborhood · ZIP 94402These 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.91
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.88
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.595

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.93%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.31%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.7.4%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.1%
PopulationHow many people live in this area.26,204
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.4,919 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$171,813
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$232,257
Average tempThe average temperature here across a full year.58°F
Annual precipHow much rain and melted snow falls here in a typical year.24 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.66%

Owner Tools

Do you own this home?
Claim this home

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

421 Sonora 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 more than 79% of homes in San Mateo County
  • Costs more per square foot than 88% of homes in San Mateo 94402
  • Smaller than 77% of homes in Aragon
  • Older than 89% of homes in San Mateo County

What homes are worth in San Mateo 94402

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

This home
$826K$5.3M

This home is worth more than 57% of homes in San Mateo 94402.

How it measures up in San Mateo 94402

The dot is this home. The mark in the middle is the typical home in San Mateo 94402.

Estimated value$2,511,152
CheaperTypical $2,372,455Pricier

Pricier than 57% of homes nearby

Price per ft²$1486
CheaperTypical $1242Pricier

Pricier than 88% of homes nearby

Living area1,690 ft²
SmallerTypical 1,920 ft²Bigger

Bigger than 36% of homes nearby

Lot size0.14 ac
SmallerTypical 0.16 acBigger

Bigger than 36% of homes nearby

Year built1939
OlderTypical 1950Newer

Newer than 28% of homes nearby

How 421 Sonora Dr ranks against every home in each area.
MeasureThis homeAragonSan Mateo 94402San Mateo County
Estimated valuepricier than$2,511,15235% of homes57% of homes79% of homes
Price per ft²pricier than$148684% of homes88% of homes87% of homes
Living areabigger than1,690 ft²23% of homes36% of homes54% of homes
Lot sizebigger than0.14 ac42% of homes36% of homes45% of homes
Year builtnewer than193967% of homes28% of homes11% of homes

About 421 Sonora Dr

How much is 421 Sonora Dr, San Mateo, CA worth?

The TopHap Estimate for 421 Sonora Dr, San Mateo, CA is $2,511,152 as of Sep 24, 2026. The likely range is $2,312,127 to $2,710,177. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 421 Sonora Dr, San Mateo, CA last sell?

421 Sonora Dr, San Mateo, CA last sold on Jun 8, 2021 for $2,500,000, according to the county's recorded deed.

How big is 421 Sonora Dr, San Mateo, CA?

421 Sonora Dr, San Mateo, CA has 3 bedrooms, 2 bathrooms, 1,690 square feet of living space and a 0.14-acre lot.

When was 421 Sonora Dr, San Mateo, CA built?

421 Sonora Dr, San Mateo, CA was built in 1939, making it 87 years old. The building has 1 story.

What schools serve 421 Sonora Dr, San Mateo, CA?

421 Sonora Dr, San Mateo, CA is assigned to Baywood Elementary School (elementary), rated A-; Aragon High School (high), rated A+; Borel Middle School (middle), rated A-. All sit in San Mateo-Foster City Elementary School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 421 Sonora Dr, San Mateo, CA compare to other homes in San Mateo 94402?

Among the 7,885 homes in San Mateo 94402, it is worth more than 57% of them ($2,511,152 against a typical $2,372,455), its price per square foot is higher than 88% of them ($1486 against a typical $1242), it is bigger than 36% of them (1,690 ft² against a typical 1,920 ft²), its lot is bigger than 36% of them (0.14 ac against a typical 0.16 ac) and it is newer than 28% of them (1939 against a typical 1950). Measured against all of San Mateo County, it is worth more than 79% 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 421 Sonora Dr, San Mateo, CA?

The 2025 property tax bill for 421 Sonora Dr, San Mateo, CA was $30,094. The county assessed it at $2,550,000.

More homes on Sonora Dr

Closest homes

More homes in San Mateo 94402

Assigned schools

Explore the area

See this home in context

Open 421 Sonora Dr on TopHap’s interactive map to compare it against every sale nearby, overlay school zones and flood risk, and run a CMA.

Open in map
A flyover of TopHap's photorealistic 3D map, with recorded sale prices pinned to homes
Search any address, city, zip, or county…3D$1.9M$6.25MOpen in map