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Single Family ResidenceResidential
$472,849$231 / 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 Oct 21, 2026
Last sold for $233,750 on Oct 16, 2015

21 KNOLL RIDGE CT

O FALLON, MO 63368
3
Beds
2
Baths
2,043 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.
0.28 ac
Lot SizeThe size of the land the home sits on, from county records.
1994
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.
6
RoomsThe total room count in county records. Counties differ on which rooms they count, so compare it loosely.
2
ParkingThe number of parking spaces on the property, including the garage.

Valuation

$473K
$449K low$496K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$233,750 · Oct 16, 2015

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,889 (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.$76,249 (2026)
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$70,242
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$401,312

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.Ranch
CountyST. CHARLES
Lot (acres)The size of the land the home sits on, from county records.0.28
FireplaceWhether the home has a fireplace, and what kind.Yes
GarageWhether the property has a garage, and details like whether it is attached to the home.Garage, Attached
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.DeckPatio · 50 ft²

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.

E
Dardenne Elementary SchoolB-
Elementary · Grades KG–5 · 0.3 mi
H
Fort Zumwalt West High SchoolA+
High · Grades 9–12 · 1.8 mi
M
Fort Zumwalt West Middle SchoolA+
Middle · Grades 6–8 · 1.8 mi

District: Fort Zumwalt R-Ii School District

Neighborhood · ZIP 63368These 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.66
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.76
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.100

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.30%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.3.2%
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.49,861
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.2,210 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$119,542
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$138,192
Average tempThe average temperature here across a full year.55°F
Annual precipHow much rain and melted snow falls here in a typical year.40 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.57%

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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 Knoll Ridge Ct 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 77% of homes in St. Charles County
  • Costs more per square foot than 84% of homes in St. Charles County
  • Has a bigger lot than 77% of homes in O Fallon 63368
  • Older than 76% of homes in O Fallon 63368

What homes are worth in O Fallon 63368

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

This home
$196K$804K

This home is worth more than 65% of homes in O Fallon 63368.

How it measures up in O Fallon 63368

The dot is this home. The mark in the middle is the typical home in O Fallon 63368.

Estimated value$472,849
CheaperTypical $420,768Pricier

Pricier than 65% of homes nearby

Price per ft²$231
CheaperTypical $184Pricier

Pricier than 83% of homes nearby

Living area2,043 ft²
SmallerTypical 2,360 ft²Bigger

Bigger than 38% of homes nearby

Lot size0.28 ac
SmallerTypical 0.23 acBigger

Bigger than 77% of homes nearby

Year built1994
OlderTypical 2000Newer

Newer than 24% of homes nearby

How 21 Knoll Ridge Ct ranks against every home in each area.
MeasureThis homeO Fallon 63368St. Charles County
Estimated valuepricier than$472,84965% of homes77% of homes
Price per ft²pricier than$23183% of homes84% of homes
Living areabigger than2,043 ft²38% of homes52% of homes
Lot sizebigger than0.28 ac77% of homes71% of homes
Year builtnewer than199424% of homes48% of homes

About 21 Knoll Ridge Ct

How much is 21 Knoll Ridge Ct, O Fallon, MO worth?

The TopHap Estimate for 21 Knoll Ridge Ct, O Fallon, MO is $472,849 as of Oct 21, 2026. The likely range is $449,357 to $496,341. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 21 Knoll Ridge Ct, O Fallon, MO last sell?

21 Knoll Ridge Ct, O Fallon, MO last sold on Oct 16, 2015 for $233,750, according to the county's recorded deed.

How big is 21 Knoll Ridge Ct, O Fallon, MO?

21 Knoll Ridge Ct, O Fallon, MO has 3 bedrooms, 2 bathrooms, 2,043 square feet of living space and a 0.28-acre lot.

When was 21 Knoll Ridge Ct, O Fallon, MO built?

21 Knoll Ridge Ct, O Fallon, MO was built in 1994, making it 32 years old. It is a ranch home. The building has 1 story.

What schools serve 21 Knoll Ridge Ct, O Fallon, MO?

21 Knoll Ridge Ct, O Fallon, MO is assigned to Dardenne Elementary School (elementary), rated B-; Fort Zumwalt West High School (high), rated A+; Fort Zumwalt West Middle School (middle), rated A+. All sit in Fort Zumwalt R-Ii School District. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 21 Knoll Ridge Ct, O Fallon, MO compare to other homes in O Fallon 63368?

Among the 15,024 homes in O Fallon 63368, it is worth more than 65% of them ($472,849 against a typical $420,768), its price per square foot is higher than 83% of them ($231 against a typical $184), it is bigger than 38% of them (2,043 ft² against a typical 2,360 ft²), its lot is bigger than 77% of them (0.28 ac against a typical 0.23 ac) and it is newer than 24% of them (1994 against a typical 2000). Measured against all of St. Charles County, it is worth more than 77% 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 Knoll Ridge Ct, O Fallon, MO?

The 2025 property tax bill for 21 Knoll Ridge Ct, O Fallon, MO was $4,889. The county assessed it at $76,249.

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