Standard flow rate is a correction applied to an actual flow measurement based on a given temperature and pressure. The correction is applied using the ideal gas law. The most widely used value is 1 atmosphere (101.3 kPa) or 14.696 psia at sea level and 59 ^{0}F (15^{0}C).

Normal flow rate is 1 atmosphere (101.3 kPa) or 14.696 psia at 32 ^{0}F (0 ^{0}C).

Actual flow rate is the actual volume of fluid that passes a given point based on given pressure and temperature of the process.