The square foot (plural square feet; abbreviated ft² or sq ft) is an imperial unit and U.S. customary unit (non-SI, non-metric) of area, used mainly in the United States, Canada, United Kingdom, Bangladesh, India and Pakistan. It is defined as the area of a square with sides of 1 foot.
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 vertical line bisecting it. It is also occasionally written as a square with a slash through it.
1 square foot is equivalent to: