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Single Family ResidenceResidential
$531,247$366 / 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 95How 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 $475,000 on Jul 30, 2024

21 MERCER ST

SOUTH RIVER, NJ 08882
0
Baths
1,453 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.
0.15 ac
Lot SizeThe size of the land the home sits on, from county records.
1963
Year BuiltThe year the home was originally built, according to county records.

Valuation

$531K
$507K low$556K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$475,000 · Jul 30, 2024

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$7,772 (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.$291,200 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$131,500
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$159,700
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$291,200
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$291,200

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.4 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.30%
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
CountyMIDDLESEX
Lot (acres)The size of the land the home sits on, from county records.0.15
PoolWhether the property has a pool, and what kind, such as in-ground.No

Transaction History(2)

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

Foreclosure Filings(5)

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

H
South River High SchoolD
High · Grades 9–12 · 0.3 mi
M
South River Middle SchoolC-
Middle · Grades 6–8 · 0.3 mi
E
South River Primary School
Elementary · Grades KG–2 · 0.5 mi

District: South River Borough School District

Neighborhood · ZIP 08882These 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.104
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.98
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.101

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.17%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.9.9%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.1.6%
PopulationHow many people live in this area.16,718
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.5,569 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$86,286
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$125,749
Average tempThe average temperature here across a full year.53°F
Annual precipHow much rain and melted snow falls here in a typical year.49 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.56%

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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

21 Mercer 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.

  • Costs more per square foot than 66% of homes in South River 08882
  • Newer than 80% of homes in South River 08882

What homes are worth in South River 08882

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

This home
$343K$935K

This home is worth more than 51% of homes in South River 08882.

How it measures up in South River 08882

The dot is this home. The mark in the middle is the typical home in South River 08882.

Estimated value$531,247
CheaperTypical $528,786Pricier

Pricier than 51% of homes nearby

Price per ft²$366
CheaperTypical $342Pricier

Pricier than 66% of homes nearby

Living area1,453 ft²
SmallerTypical 1,556 ft²Bigger

Bigger than 40% of homes nearby

Lot size0.15 ac
SmallerTypical 0.14 acBigger

Bigger than 57% of homes nearby

Year built1963
OlderTypical 1950Newer

Newer than 80% of homes nearby

How 21 Mercer St ranks against every home in each area.
MeasureThis homeSouth River 08882Middlesex County
Estimated valuepricier than$531,24751% of homes38% of homes
Price per ft²pricier than$36666% of homes54% of homes
Living areabigger than1,453 ft²40% of homes39% of homes
Lot sizebigger than0.15 ac57% of homes50% of homes
Year builtnewer than196380% of homes45% of homes

About 21 Mercer St

How much is 21 Mercer St, South River, NJ worth?

The TopHap Estimate for 21 Mercer St, South River, NJ is $531,247 as of Sep 24, 2026. The likely range is $506,801 to $555,693. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Mercer St, South River, NJ last sell?

21 Mercer St, South River, NJ last sold on Jul 30, 2024 for $475,000, according to the county's recorded deed. TopHap holds 2 recorded sales for this parcel.

How big is 21 Mercer St, South River, NJ?

21 Mercer St, South River, NJ has 1,453 square feet of living space and a 0.15-acre lot.

When was 21 Mercer St, South River, NJ built?

21 Mercer St, South River, NJ was built in 1963, making it 63 years old.

What schools serve 21 Mercer St, South River, NJ?

21 Mercer St, South River, NJ is assigned to South River High School (high), rated D; South River Middle School (middle), rated C-; South River Primary School (elementary). All sit in South River Borough School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Mercer St, South River, NJ compare to other homes in South River 08882?

Among the 4,333 homes in South River 08882, it is worth more than 51% of them ($531,247 against a typical $528,786), its price per square foot is higher than 66% of them ($366 against a typical $342), it is bigger than 40% of them (1,453 ft² against a typical 1,556 ft²), its lot is bigger than 57% of them (0.15 ac against a typical 0.14 ac) and it is newer than 80% of them (1963 against a typical 1950). Measured against all of Middlesex County, it is worth more than 38% 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 21 Mercer St, South River, NJ?

The 2025 property tax bill for 21 Mercer St, South River, NJ was $7,772. The county assessed it at $291,200.

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Assigned schools

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