Specific Speed (Ns) Calculator

Specific speed (ns) is a fundamental key figure in pump technology. It serves to compare impellers of different sizes under similar operating conditions and to determine the optimal design (radial, mixed-flow, or axial).

Design and Characterization of Impeller Geometries:

Calculation Basis (Formula):

The calculation is carried out according to the internationally used formula (SI units):

Definition of Variables:

• n (Rotational Speed): The operating speed of the pump in revolutions per minute (rpm).

• Q (Flow Rate): The volume flow rate at the Best Efficiency Point (BEP) in [m^3/s].

• H (Head): The generated head per stage in [m].