The square foot is an Imperial unit / U.S. customary unit (non-SI non-metric) of area, used in the United States. It is defined as the area of a square with sides of 1 foot (0.3 yards, 12 inches, or 0.3048 metres) in length. The Imperial units or the Imperial system is a collection of English units, first defined in the Weights and Measures Act of 1824, later refined (until 1959) and reduced. ... The U.S. customary units (more commonly known in the US as English units or standard units) are the non-metric units of measurement that are presently used in the United States, in some cases alongside the metric system of units. ... Cover of brochure The International System of Units. ... The International System of Units (symbol: SI) (for the French phrase Syst me International dUnit s) is the most widely used system of units. ... Area is a physical quantity expressing the size of a part of a surface. ... In plane geometry, a square is a polygon with four equal sides and equal angles. ... This article is about a foot as a unit of length. ... This article is about the unit of measure known as the yard. ... Mid-19th century tool for converting between different standards of the inch An inch is an Imperial and U.S. customary unit of length. ... The metre, or meter, is a measure of length. ... In general English usage, length (symbols: l, L) is but one particular instance of distance – an objects length is how long the object is – but in the physical sciences and engineering, the word length is in some contexts used synonymously with distance. Height is vertical distance; width (or breadth...

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.

Conversions

1 square foot is equivalent to:

• 144 square inches
• 0.111--> square yards
• 0.01 "squares". (A square is a unit used in Australia before metrication (and since) to measure the floor area of a house. 1 "square" = 100 sq. ft.)
• ≈0.00002295684110 acres
• ≈92 903.04 square millimetres
• ≈929.0304 square centimetres
• ≈0.09290304 square metres
• ≈0.000000092903040 square kilometres

A square inch is by definition the area enclosed by a square with sides each 1 inch long. ... -1... An acre is an English unit of area, which is also frequently used in the United States and some Commonwealth countries. ... The metre, symbol: m, is the basic unit of distance (or of length, in the parlance of the physical sciences) in the International System of Units. ... cm redirects here, alternate uses: cm (disambiguation) A centimetre (symbol cm; American spelling: centimeter) is an SI unit of length. ... A square metre (US spelling: square meter) is by definition the area enclosed by a square with sides each 1 metre long. ... Square kilometre (US spelling: Square kilometer), symbol km², is an SI unit of surface area. ...

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