Pump Head Pressure Calculator

How it is calculated

The tool adds three heads, all in metres of water column.

friction head = pipe_length × friction_loss ÷ 100
pressure head = pressure_bar × 10.1972
total head = static_lift + friction head + pressure head
total in bar = total head ÷ 10.1972

Static Lift is the vertical rise in m, Pipe Length the pipe run in m, Friction Loss is the head lost per 100 m of pipe (m/100 m), and Required Outlet Pressure is the pressure wanted at the outlet. You must supply the friction figure yourself from the pipe size, flow rate and material; the tool does not work it out. Inputs cannot be negative, all four fields are required, and a friction loss above 100 m per 100 m of pipe, or a total of zero, gives no result. Results are rounded to two decimals. Fittings and valves are not added separately.

Common mistakes

• Entering the total friction loss of the pipe in the friction field. It is the loss per 100 m; the tool multiplies by the length itself.
• Leaving the outlet pressure at zero for a sprinkler or nozzle that needs, say, 2 bar. The pressure head is then missing from the total.
• Typing the pressure in psi or kPa. The field is bar, so 30 psi is about 2.1 bar.
• Entering the horizontal distance as static lift. Only the vertical rise counts there; the horizontal run goes in pipe length.
• Ignoring that the friction figure depends on the flow rate. A value looked up for a low flow will understate the head if the pump delivers more.