Hydraulic horsepower formula?

HHP = (Q × H × SG) / 3960 (US) or Q × H × SG / (367.2 × η) in kW

Typical pump efficiency?

Centrifugal: 70–85% | Positive displacement: 80–95%

AutoEngCalc - Engineering Calculators

Calculate hydraulic horsepower, brake horsepower (BHP), wire horsepower (WHP) and pump efficiency for centrifugal and positive displacement pumps.

Brake Horsepower BHP

25.4 HP

Q=100 m³/h, H=50m, η=80%

Featured: Hydraulic HP • BHP • WHP • Efficiency

Flow Rate Q m³/h or GPM

Total Head H m or ft

Specific Gravity SG

Pump Efficiency η_p (%)

Motor Efficiency η_m (%)

Units System

Required power at different efficiencies

Hydraulic HP = (Q × H × SG) / 3960 (US)
Hydraulic kW = (Q × H × SG) / 367.2 (metric)
BHP = Hydraulic / η_p
WHP = BHP / η_m

Enter pump parameters to see results

Centrifugal: 70–85%

PD (piston): 85–95%

Motor: 88–95%

Select pump near BEP

Oversize motor by 10–20%

Consider NPSH margin

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