Total head
According to DIN EN ISO 17769-1, the total head (H) is the energy of mass of the fluid handled, divided by the acceleration due to gravity. The total head is expressed in metres (m).

z Geodetic height of given point above BN
pb Atmospheric pressure
p Overpressure (positive) or underpressure (negative) in relation to pb
ρ Density of fluid handled
g Gravitational acceleration
v Flow velocity
A graphic representation of the total head at various points within a pump system can be found in DIN EN ISO 17769-1, for example. See Fig. 1 Specific energy