Decimal-Acre Reference / Sheet 0.01
0.01 Acres = 436 sq ft
The floor of the decimal-acre scale. Most US tax assessors round to two decimal places, so anything between roughly 218 and 654 square feet shows as "0.01 acres" on a public record. The math is exact: 0.01 multiplied by 43,560 equals 435.6 square feet.
Square Feet
435.6
international ft2
Square Metres
40.47
m2
Hectares
0.0040
ha
Derivation: 0.01 acres × 43,560 sq ft per acre = 435.6 sq ft, exactly. From the 1959 IYPA international acre.
Sheet 02 · The Floor of the Scale
Why 0.01 acres exists as a recorded parcel
A 0.01-acre parcel is a strange creature in the property record. It is too small to build on under any US zoning code, too small to subdivide further, too small to host a freestanding commercial use beyond a kiosk, and yet it appears with surprising frequency on county GIS maps and tax-assessor pages. The reason is that the legal record can carve land into much smaller pieces than the physical world tends to host. Every utility easement, every airspace condo allocation, every road-taking remainder, every encroachment correction, and every minor subdivision residual can produce a parcel below 1,000 sq ft that the assessor must give a parcel ID and a tax value.
The most common 0.01-acre parcel by raw count is the utility-substation pad. Public power utilities operate hundreds to thousands of distribution-class substations across their service territory, each typically a 30-foot-by-15-foot fenced compound (450 sq ft, just over 0.01 acres). Each compound is recorded as a separate parcel in the county records, with the utility paying the property tax. Telecommunications has a similar pattern: small-cell base stations on light poles, distributed antenna sites, and street-cabinet vaults all record as small parcels in the right-of-way.
The second-most-common is the condo airspace allocation. When a high-rise apartment building is condo-mapped, each unit gets a recorded fee-simple parcel that maps to the airspace defined by the unit walls. The recorded land area for that parcel is sometimes computed as the building footprint divided by the number of units, which for a 12-story building with 100 units on a 50,000 sq ft footprint produces 500 sq ft per unit (0.011 acres). On the assessor record this shows as 0.01 acres, even though no individual unit owner actually has 500 sq ft of ground.
The third pattern is the road-taking remainder. State DOT projects often produce 5-foot-wide by 50-foot-long strips of land on the new right-of-way side of an old road, which the original owner retains but cannot effectively use. These 250 sq ft strips round to 0.01 acres on the tax record. A typical metro-area county will have hundreds to thousands of these residual parcels, especially in areas where the highway system was built incrementally between the 1950s and 1990s.
Finally, sidewalk and ADA-ramp dedications to the city produce 0.01-acre parcels at street corners. When a city redesigns an intersection for accessibility compliance, it acquires small triangular wedges from the corner properties to install the ramp. These wedges are recorded as separate parcels owned by the city and tax-exempt.
Sheet 03 · What 436 Sq Ft Looks Like
Visual scale for one hundredth of an acre
For an intuitive feel for 435.6 sq ft, the most useful interior comparison is a one-car garage. A spacious one-car garage of 20 ft by 22 ft is 440 sq ft, almost exactly 0.01 acres. A typical New York City studio apartment averages 400 to 500 sq ft, so 0.01 acres is a small studio floor. A standard hotel king-bed room is 325 to 425 sq ft, so 0.01 acres is just over a hotel room. A two-bedroom mobile home single-wide of 12 ft by 36 ft is 432 sq ft, almost exactly the same.
For outdoor reference, an NBA basketball court's three-second restricted area (the painted lane between the free-throw line and the baseline) is exactly 380 sq ft, so 0.01 acres is about 1.15 free-throw lanes. A regulation boxing ring at 20 ft by 20 ft is 400 sq ft. A standard four-court tennis paddle pickleball complex needs about 7,200 sq ft, so 0.01 acres is about 6 percent of a pickleball complex. A single tour-grade swimming-pool lane (50 m long by 2.5 m wide) translates to 1,346 sq ft, so 0.01 acres is about 32 percent of a single pool lane.
The smallest legal residential parcel in California after a Senate Bill 9 lot split is 1,200 sq ft, which is 2.75 times larger than 0.01 acres. The smallest pre-zoning historic urban lots in cities like Charleston and Savannah occasionally clock in below 1,000 sq ft, but these are rare and usually grandfathered. For practical purposes, 0.01 acres is a clerical floor: the smallest acreage you will see on a deed before assessors round to zero.