The square foot (pl. square feet; abbreviated sq ft, sf, or ft2; also denoted by '2 and ) is an imperial unit and U.S. customary unit (non-SI, non-metric) of area, used mainly in the United States and partially in Canada, the United Kingdom, Bangladesh, India, Nepal, Pakistan, Ghana, Liberia, Malaysia, Myanmar, Singapore and Hong Kong.[citation needed] It is defined as the area of a square with sides of 1 foot.

square foot
Unit systemImperial, United States customary units
Unit ofarea
Symbolft2, sq ft
1 ft2 in ...... is equal to ...
  • 144 sq in
  • 1/9 sq yd
   SI units   
  • 929.0304 cm2
  • 0.0929 m2
Comparison of 1 square foot with some Imperial and metric units of area

Although the pluralization is regular in the noun form, when used as an adjective, the singular is preferred. So, an apartment measuring 700 square feet could be described as a 700 square-foot apartment.[citation needed] This corresponds to common linguistic usage of foot.

The square foot unit is commonly used in real estate.[1] Dimensions are generally taken with a laser device, the latest in a long line of tools used to gauge the size of apartments[2] or other spaces. Real estate agents often measure straight corner-to-corner, then deduct non-heated spaces, and add heated spaces whose footprints exceed the end-to-end measurement.[3]

1 square foot conversion to other units of area:

  • 1 square foot (ft2) = 0.000022956341 acres (ac)
  • 1 square foot (ft2) = 0.000009290304 hectare (ha)
  • 1 square foot (ft2) = 0.09290304 square meters (m2)
  • 1 square foot (ft2) = 144 square inches (in2)
  • 1 square foot (ft2) = 0.111111111111 square yards (yd2)
  • 1 square foot (ft2) = 929.0304014422 square centimeters (cm2)
  • 1 square foot (ft2) = 9.290304 square decimeters (dm2)
  • 1 square foot (ft2) = 0.00000009290304 square kilometers (km2)
  • 1 square foot (ft2) = 144,003,673,094,580 square microinches (μin2)
  • 1 square foot (ft2) = 92,903,040,000 square micrometers (μm2)
  • 1 square foot (ft2) = 0.0000000358701 square miles (mi2)
  • 1 square foot (ft2) = 92,903.04 square millimeters (mm2)

See also



  1. ^ "How to Find the Square Feet of Your Office Space". SquareFoot Blog. 2020-01-06. Retrieved 2020-01-14.
  2. ^ Santora, Marc (2010-12-17). "The Elusive Measure Known as the Square Foot". The New York Times. ISSN 0362-4331. Retrieved 2020-01-14.
  3. ^ "Square Foot Calculator | How to Measure Square Feet". Home Improvement Tips & Advice from HomeAdvisor. 2016-01-04. Retrieved 2020-01-14.