SCFM stands for Standard Cubic Feet per Minute, which is a measurement of airflow at a standard temperature, standard atmospheric pressure, and standard humidity. It is the molar flow rate of a gas expressed as a volumetric flow at a "standardized" temperature and pressure, representing a fixed number of moles of gas regardless of composition and actual flow conditions. The standard temperature for calculating SCFM flow rate ranges from 60°F to 68°F, at a pressure of 14.7 psi and relative humidity of 36%.

SCFM is used to measure the flow rate of a gas or air through a compressor at standard temperature and pressure conditions. It is important to note that SCFM measures volumetric airflow at standard conditions, and it will always be higher than the CFM value for an air compressor. CFM, or Cubic Feet per Minute, measures the volume of air that the air compressor delivers to pneumatic tools, and the temperature and pressure components are variable. Essentially, volumetric flow rate in CFM indicates the air flow rate measured for actual conditions, i.e. actual temperature, and actual pressure.

The distinction between SCFM and CFM is important because air density changes with pressure and temperature. The CFM rating of an air compressor will always be lower than its SCFM rating because most manufacturers measure the CFM at a point where the air pressure is lower or equal to 90 PSI. SCFM is often used extensively in scientific research, pharmaceutical production, or other high-precision needs.