cubic foot
Unit systemImperial and US Customary
Unit ofVolume
Symbolft3 or cu ft
1 ft3 in ...... is equal to ...
   US Customary   1728 in3
127 yd3
   SI units   0.02831685 m3

The cubic foot (symbol ft3 or cu ft)[1] is an imperial and US customary (non-metric) unit of volume, used in the United States and the United Kingdom. It is defined as the volume of a cube with sides of one foot (0.3048 m) in length. Its volume is 28.3168 L (about 135 of a cubic metre).

At 60 °F (16 °C), a cubic foot of water weighs 62.37 pounds (28.29 kg).


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1 cubic foot  = 1728 cubic inches
= 127 of a cubic yard
0.037037 yd3
= 0.028316846592 m3
= 28.316846592 L
= 57677 US fluid gallons
7.4805 US fl gal
= 7372877 US fluid ounces
957.5065 US fl oz
≈ 6.2288 imperial gallons
≈ 996.61 imperial fluid ounces
≈ 0.80356 US bushels
≈ 0.17811 oil barrel

Symbols and abbreviations

The IEEE symbol for the cubic foot is ft3.[1] The following abbreviations are used: cubic feet, cubic foot, cubic ft, cu feet, cu foot, cu ft, cu.ft, cuft, cb ft, cb.ft, cbft, cbf, feet3, foot3, ft3, feet/-3, foot/-3, ft/-3.[citation needed]

Larger multiples are in common usage in commerce and industry in the USA:

Cubic foot per second and related flow rates

"Cusec" redirects here. For other uses, see Canadian University Software Engineering Conference.

The IEEE symbol for the cubic foot per second is ft3/s.[1] The following other abbreviations are also sometimes used:

The flow or discharge of rivers, i.e., the volume of water passing a location per unit of time, is commonly expressed in units of cubic feet per second or cubic metres per second.

Cusec is a unit of flow rate,[2] used mostly in the United States in the context of water flow, particularly of rivers and canals.

Conversions: 1 ft3s−1 = 0.028316847 m3⋅s−1 = 28.316847 L⋅s−1 = 1.699 m3⋅min−1 = 1699 L⋅min−1

Cubic foot per minute

The IEEE symbol for the cubic foot per minute is ft3/min.[1] The following abbreviations are used:

Cubic feet per minute is used to measure the amount of air that is being delivered, and is a common metric used for carburettors,[3] pneumatic tools, and air-compressor systems.[4]

Standard cubic foot

Main articles: Standard cubic foot and Standard cubic foot per minute

A standard cubic foot (abbreviated scf) is a measure of quantity of gas, sometimes[clarification needed] defined in terms of standard temperature and pressure as a cubic foot of volume at 60 degrees Fahrenheit (15.56 °C; 288.71 K) and 14.7 pounds per square inch (PSI) (1.01 bar; 101.35 kPa) of pressure.[citation needed]

See also


  1. ^ a b c d IEEE Standard Letter Symbols for Units of Measurement (SI Customary Inch-Pound Units, and Certain Other Units) (PDF or hardcopy). (Revision of IEEE Std 260.1-1993). IEEE Std 260.1-2004 (2004 ed.). Piscataway, N.J.: IEEE. 2004-09-24. pp. 1–30. doi:10.1109/IEEESTD.2004.94618. ISBN 978-1-5044-0928-5. STD95220 STDPD95220 STDPL95220. Retrieved 22 December 2019. [1], ISBN 978-0-7381-3997-5, ISBN 978-0-7381-3998-2.
  2. ^ Rowlett, Russ. "Units: C". How Many? A Dictionary of Units of Measurement. University of North Carolina at Chapel Hill. Archived from the original on January 9, 2018. Retrieved August 2, 2020.
  3. ^ "Carburetor CFM Racing". Summit Racing. Retrieved February 7, 2019.
  4. ^ "Easy Guide to Rotary Screw Air Compressors for Vehicles". October 16, 2018. Retrieved October 30, 2018.