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Single Family ResidenceResidential
$338,714$183 / 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 Aug 30, 2026

421 S RIVER RD

ALGONQUIN, IL 60102
1
Baths
1,848 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.
0.2 ac
Lot SizeThe size of the land the home sits on, from county records.
1920
Year BuiltThe year the home was originally built, according to county records.
2
StoriesHow many floors the home has above ground.

Valuation

$339K
$322K low$356K high

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$5,203 (2024)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$82,511 (2024)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$10,775
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$71,736
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$73,796
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$247,533

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.Cape Cod
CountyMcHenry
Lot (acres)The size of the land the home sits on, from county records.0.20
HeatingThe type of heating system in the home.Forced Air

Transaction History(1)

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.

M
Algonquin Middle SchoolB
Middle · Grades 6–8 · 0.5 mi
E
Eastview Elementary SchoolA
Elementary · Grades KG–5 · 0.5 mi
H
Dundee-Crown High SchoolB
High · Grades 9–12 · 2.2 mi

District: Community Unit School District 300

Neighborhood · ZIP 60102These 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.111
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.48

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.97%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.26%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.7%
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.29,705
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,882 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$126,290
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$145,923
Average tempThe average temperature here across a full year.48°F
Annual precipHow much rain and melted snow falls here in a typical year.37 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.54%

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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

421 S River Rd 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 76% of homes in Algonquin 60102
  • Costs less per square foot than 80% of homes in Algonquin 60102
  • Has a smaller lot than 83% of homes in Algonquin 60102
  • Among the oldest homes in Algonquin 60102

What homes are worth in Algonquin 60102

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

This home
$239K$676K

This home is worth more than 24% of homes in Algonquin 60102.

How it measures up in Algonquin 60102

The dot is this home. The mark in the middle is the typical home in Algonquin 60102.

Estimated value$338,714
CheaperTypical $425,742Pricier

Pricier than 24% of homes nearby

Price per ft²$183
CheaperTypical $204Pricier

Pricier than 20% of homes nearby

Living area1,848 ft²
SmallerTypical 1,998 ft²Bigger

Bigger than 43% of homes nearby

Lot size0.2 ac
SmallerTypical 0.27 acBigger

Bigger than 17% of homes nearby

Year built1920
OlderTypical 1993Newer

Older than almost all homes nearby

How 421 S River Rd ranks against every home in each area.
MeasureThis homeAlgonquin 60102McHenry County
Estimated valuepricier than$338,71424% of homes43% of homes
Price per ft²pricier than$18320% of homes28% of homes
Living areabigger than1,848 ft²43% of homes54% of homes
Lot sizebigger than0.2 ac17% of homes27% of homes
Year builtnewer than1920almost no homes3% of homes

About 421 S River Rd

How much is 421 S River Rd, Algonquin, IL worth?

The TopHap Estimate for 421 S River Rd, Algonquin, IL is $338,714 as of Aug 30, 2026. The likely range is $321,799 to $355,629. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

How big is 421 S River Rd, Algonquin, IL?

421 S River Rd, Algonquin, IL has 1 bathrooms, 1,848 square feet of living space and a 0.20-acre lot.

When was 421 S River Rd, Algonquin, IL built?

421 S River Rd, Algonquin, IL was built in 1920, making it 106 years old. It is a cape cod home. The building has 2 stories.

What schools serve 421 S River Rd, Algonquin, IL?

421 S River Rd, Algonquin, IL is assigned to Algonquin Middle School (middle), rated B; Eastview Elementary School (elementary), rated A; Dundee-Crown High School (high), rated B. All sit in Community Unit School District 300. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 421 S River Rd, Algonquin, IL compare to other homes in Algonquin 60102?

Among the 11,780 homes in Algonquin 60102, it is worth more than 24% of them ($338,714 against a typical $425,742), its price per square foot is higher than 20% of them ($183 against a typical $204), it is bigger than 43% of them (1,848 ft² against a typical 1,998 ft²), its lot is bigger than 17% of them (0.2 ac against a typical 0.27 ac) and it is newer than almost none of them (1920 against a typical 1993). Measured against all of McHenry County, it is worth more than 43% 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 S River Rd, Algonquin, IL?

The 2024 property tax bill for 421 S River Rd, Algonquin, IL was $5,203. The county assessed it at $82,511.

More homes on S River Rd

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More homes in Algonquin 60102

Assigned schools

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