Cubic foot

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, or exactly 28.316846592 L, which is very close to ⁠1/35⁠ of a cubic metre).

cubic foot
Gas meter with volume measured in cubic feet
General information
Unit system	Imperial and US Customary
Unit of	Volume
Symbol	ft3, cu ft
Conversions
1 ft3 in ...	... is equal to ...
US Customary	1728 in3 1⁄27 yd3
SI units	0.028316846592 m3

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.^[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 United States:

• CCF or HCF: Centum (Latin hundred) cubic feet; i.e., 100 cu ft (2.8 m³)
  • Used in the billing of natural gas and water delivered to households.
• MCF: Mille (Latin thousand) cubic feet; i.e., 1,000 cu ft (28.3 m³)
• MMCF: Mille mille (= million) cubic feet; i.e., 1,000,000 cu ft (28,320 m³)
• MMCFD: MMCF per day; i.e., 1000000 ft³/d
  • Used in the oil and gas industry.
• BCF or TMC: Billion or thousand million cubic feet; i.e., 1,000,000,000 cu ft (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., 1000000000000 ft³
  • 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.^[1] 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,^[2] used mostly in the United States in the context of water flow, particularly of rivers and canals.

Conversions: 1 ft³s⁻¹ = 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.^[1] 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,^[3] pneumatic tools, and air-compressor systems.^[4]

Standard cubic foot

Main article: Standard cubic foot

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

See also

• Board foot
• Conversion of units
• Cord (unit)
• Cube (arithmetic), cube root
• Cubic inch
• Cubic yard
• Orders of magnitude (volume) for a comparison with other volumes
  • Orders of magnitude (one cubic millimetre to one cubic metre)
• Square foot
• Therm, a unit of natural gas approximately equal to 100 cubic feet
• Cubic metre per second