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 1⁄35 of a cubic metre).

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

Conversions

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 ft³
  • Used in the billing of natural gas and water delivered to households.
• MCF: Mille (Latin thousand) cubic feet; i.e., 1000 ft³
• MMCF: Mille mille cubic feet; i.e., 1000000 ft³
• 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., 1000000000 ft³
  • 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 = 0.028316847 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:

• 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 carburettors,^[3] pneumatic tools, and air-compressor systems.^[4]

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 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]}