Definitions

# Square foot

The square foot is an imperial unit / U.S. customary unit (non-SI non-metric) of area, used mainly in the United States and United Kingdom. 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.

## 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
• the equation is length times width.

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:

1 inch = 2.54 centimetres

1 square metre = 10.764 square feet

## Conversions

1 square foot is equivalent to:

## 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: