The cubic foot (symbol ft3 or cu ft) 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, or exactly 28.316846592 L (which differs by about 1% from ⁠1/35⁠ of a cubic metre, making that a suitable approximation in many cases).

Conversions

1 cubic foot≡ 1728 cubic inches
≡ ⁠1/27⁠ of a cubic yard
≡ 28.316846592 L
≡ ⁠7+37/77⁠ US gallons
≡ ⁠957+39/77⁠ US fluid ounces
≈ 6.228835 imperial gallons
≈ 996.6137 imperial fluid ounces
≡ ⁠86400/107521⁠ US bushels
≈ 0.7786044 imperial bushels
≡ ⁠96/539⁠ oil barrel

Symbols and abbreviations

The IEEE symbol for the cubic foot is ft3. The following abbreviations are used: cubicfeet, cubicfoot, cubicft, cufeet, cufoot, cuft, cu.ft, cuft, cbft, 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 United States:

  • CCF or HCF: Centum (Latin hundred) cubic feet; i.e., 100 ft3 (2.8 m3) Used in the billing of natural gas and water supply delivered to households.
  • MCF: Mille (Latin thousand) cubic feet; i.e., 1,000 ft3 (28.3 m3)
  • MMCF: Mille mille (= million) cubic feet; i.e., 1,000,000 ft3 (28,320 m3)
  • MMCFD: MMCF per day; i.e., 1,000,000 cu ft/d (28,000 m3/d) Used in the oil and gas industry.
  • BCF or TMC: Billion or thousand million cubic feet; i.e., 1,000,000,000 ft3 (28,320,000 m3) TMC is usually used for referring to storage capacity and actual storage volume of storage dams.
  • TCF: Trillion cubic feet; i.e., 1,000,000,000,000 ft3 (2.8×1010 m3) Used in the oil and gas industry.

Cubic foot per second and related flow rates

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

  • ft3/sec
  • cu ft/s
  • cfs or CFS
  • cusec
  • second-feet

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, used mostly in the United States in the context of water flow, particularly of rivers and canals.

Conversions: 1 ft3/s = 0.0283168 m3/s = 28.3168 L/s = 1.699011 m3/min = 1,699.011 L/min

Cubic foot per minute

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

  • cu ft/min
  • cufm
  • cfm or CFM
  • cfpm or CFPM

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

Standard cubic foot

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 °F (16 °C; 289 K) and 14.7 pounds per square inch (1.01 bar; 101 kPa) of pressure.[citation needed]

See also