The cubic foot (symbol ft^{3} 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).

The IEEE symbol for the cubic foot is ft^{3}.^{[1]} The following abbreviations are used: cubicfeet, cubicfoot, cubicft, cufeet, cufoot, cuft, cu.ft, cuft, cbft, cb.ft, cbft, cbf, feet^{3}, foot^{3}, ft^{3}, 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 ft^{3}

The IEEE symbol for the cubic foot per second is ft^{3}/s.^{[1]} The following other abbreviations are also sometimes used:

ft^{3}/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.

The IEEE symbol for the cubic foot per minute is ft^{3}/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]}

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]}