The square foot is an imperial unit / U.S. customary unit (non-SI non-metric) of area, used mainly in the United States, the United Kingdom, and Canada. It is defined as the area of a square with sides of 1 foot (0.333... yards, 12 inches, or 0.3048 metres) in length. For comparison, the average one-family house in the United States in 2007 had a total floor area of approximately 2500 square feet.^[1]

Contents 1 Symbols 2 Conversions 3 Historical Use 4 References 5 See also

[edit] Symbols

There is no universally agreed symbol but the following are used:

• square feet, square foot, square ft
• sq feet, sq foot, sq ft, SF
• feet/-2, foot/-2, ft/-2
• feet^2, foot^2, ft^2
• feet², foot², ft²

A symbol for square foot, square feet, and "per square foot" commonly used in architecture, real estate and interior space plans is a simple square with a slash through it. It is also occasionally written as a square with a vertical line bisecting it!

[edit] Conversions

1 square foot is equivalent to:

• A block 12 inches by 12 inches has a square foot area of 1 square foot. 12 inches is equal to 1 foot.
• 144 square inches
• 1/9 square yards
• 0.01 "squares". (A square is a unit used in roofing to measure the area of a roof and is also a unit used in Australia before metrication (and since) to measure the floor area of a house. 1 "square" = 100 sq ft)
• ≈0.00002295684 acres
• 92 903.04 square millimetres
• 929.0304 square centimetres
• 0.09290304 square metres
• 0.000000092903040 square kilometres

[edit] Historical Use

Before metrication, the square foot was in use throughout Europe, as part of the traditional system of measurement, which showed considerable local variation. Some examples below:

• Bavarian square foot = 0.0864751 m²
• Prussian square foot = 0.098504 m²
• Viennese square foot = 0.099921 m²
• Parisian square foot = 0.105521 m² ^[2]

[edit] References

[edit] See also

• 1 E-1 m² for a comparison with other areas
• Cubic foot
• Orders of magnitude (area)
• Conversion of units
• Area (geometry)
• Square (algebra), square root
• Miscellaneous Technical (Unicode) for a list of miscellaneous technical symbols and fonts which support the square foot symbol