Pump Head & Pump Selection Calculator
The Pump Head and Selection Calculator is designed to help engineers, plumbers, and homeowners choose the right pump for their system. By inputting flow rate, pipe length, diameter, fittings, and elevation differences, you can quickly determine the total dynamic head (TDH) and select the best pump for your needs.
Why pump head calculation matters
Choosing a pump without proper head calculation can lead to:
⚠️ Undersized pumps – insufficient pressure, poor performance
💸 Oversized pumps – wasted energy, higher operating costs
🔧 Premature wear – cavitation and efficiency loss
A properly sized pump ensures:
How the calculator works
The pump head is the total resistance a pump must overcome to move fluid through a system. It combines:
Static head – elevation difference between suction and discharge points
Friction head – pressure losses from pipe walls, fittings, and valves
Pressure head – required system pressure at the outlet
Formula for Total Dynamic Head (TDH):
TDH=Hstatic+Hfriction+HpressureTDH = H_{static} + H_{friction} + H_{pressure}TDH=Hstatic+Hfriction+Hpressure
Where:
HstaticH_{static}Hstatic = Elevation difference (m or ft)
HfrictionH_{friction}Hfriction = Losses from pipes/fittings (calculated via Darcy–Weisbach or Hazen–Williams)
HpressureH_{pressure}Hpressure = Desired outlet pressure converted to head
Example calculation
Flow rate: 20 L/min
Pipe length: 30 m, diameter: 25 mm
Fittings: 6 elbows + 1 valve
Static lift: 5 m
Required outlet pressure: 2 bar (20 m head)
✅ Static head = 5 m
✅ Friction losses ≈ 4 m
✅ Pressure head = 20 m
Total Dynamic Head = 29 m
This means you need a pump capable of 20 L/min at ~30 m head.
Pump selection tips
📈 Check the pump curve – ensure the flow rate matches the head requirement
⚡ Account for efficiency – centrifugal pumps lose efficiency at extremes
🔍 Add safety margin – typically 10–15% head margin
🌡️ Consider fluid type – viscosity, temperature, and density affect head
🏠 Domestic systems – look for WRAS-approved pumps if used for drinking water
Applications
🚰 Domestic water supply systems
🌱 Irrigation & agriculture pumps
🔥 Boiler feed & heating circulation
🏭 Industrial fluid handling
💧 Wastewater & sump pumps
FAQs
Q: What is pump head?
Pump head is the measure of the energy imparted by a pump, expressed in meters (or feet) of fluid.
Q: What’s the difference between head and pressure?
Head is height (m/ft), while pressure is force per area (bar/psi). They are directly related:
Head(m)=Pressure(bar)×10.2Fluid DensityHead (m) = \frac{Pressure (bar) \times 10.2}{Fluid\ Density}Head(m)=Fluid DensityPressure(bar)×10.2
Q: Can I oversize a pump?
Yes, but it wastes energy and may damage the system. Correct sizing is crucial.
Q: Do I need to consider NPSH?
Yes, especially in industrial systems. Net Positive Suction Head prevents cavitation.