Square feet

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Physical unit
Unit name Square feet
Unit symbol
Physical quantity (s) surface
Formula symbol
system Anglo-American system of measurement
In SI units
In CGS units
Derived from foot
See also: square inches

The square feet ( square foot , plural square feet ) is a square measure in the Anglo-American system of measurement , which in the US and in the UK is used. It was used as a historical measure in continental Europe until the introduction of the metric system.

A square is defined as a square area having an edge length of 1 foot (corresponding to 1 / 3  Yard , 12  inch (inches) or 0.3048 meters ). This corresponds to approx. 0.09 square meters .


There is no generally accepted abbreviation for the unit. The following variants are in use:

  • square feet, square foot, square ft
  • sq feet, sq foot, sq ft, SF

More rarely also:

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

In architectural drawings and in real estate trading, a square is also used as a symbol, which is divided by an oblique or vertical line.


1 square foot corresponds in the Anglo-American system of measurement:

In the metric or international system of units (SI) :

Historic measure in continental Europe

Before the introduction of the metric system in the course of the 19th century, the square foot (abbr .: Qu.-F. or ◻ ') was also a common measure of area in continental Europe. It differed from country to country, depending on the different foot norms.

For example B .:

  • 1 Bavarian Qu.-F. = 0.086475 m²
  • 1 Prussian Qu.-F. = 0.098504 m²
  • 1 Viennese Qu.-F. = 0.099921 m²
  • 1 Parisian Qu.-F. = 0.105521 m²

In Bavaria, but occasionally also in other German regions, a distinction was made between ten and twelve-part square feet. The former was 100 square inches, the latter 144 square inches.


  1. Das Hauslexikon , Vol. VI, Breitkopf and Härtel, Leipzig 1837, p. 596.
  2. Leopold Einsle: Systematic compilation of the most excellent European measures, weights and coins. Publishing house Jos. Kösel'sche Buchhandlung, Kempten 1846, p. 48.

See also