How is pump shaft power calculated?

P_shaft = (ρ × g × Q × H) / η_pump, where ρ is fluid density (kg/m³), g = 9.81 m/s², Q is flow rate (m³/s), H is total head (m), and η_pump is pump efficiency (typically 0.60–0.85). Motor power = P_shaft / η_motor.

What efficiency should I assume for a centrifugal pump?

Efficiency varies with pump size and design: small pumps (<10 kW) typically achieve 50–65%, medium pumps achieve 70–80%, and large pumps can reach 85–90%. Always refer to the manufacturer's pump curve at the design operating point.

Centrifugal Pump Power Calculator

Calculate hydraulic power, shaft power, and motor power required for centrifugal pumps accounting for pump and motor efficiency.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Calculate hydraulic power, shaft power, and motor power required for centrifugal pumps accounting for pump and motor efficiency. Use the pump power result to inform your clinical assessment.

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Frequently Asked Questions

How is pump shaft power calculated?

What efficiency should I assume for a centrifugal pump?