Pump Sizing Calculator — Head, Flow, Curve

What does pump efficiency mean here?

Efficiency is the fraction of input shaft power that becomes useful hydraulic power, entered as a decimal between 0 and 1. Small centrifugal pumps often run around 0.5–0.7, so lower efficiency means more brake horsepower for the same flow and head. The figure should come from the pump curve at your design operating point.

Related questions

• How do I calculate pump horsepower from GPM and head?
• Why round up to the next standard motor size?