How to calculate pump power?

Pump power calculation can be carried out by following formula: 

Pump power consumption
Np = Rho x g x Q x H

Np -Useful power, W
Rho - Density of the pumped medium, kg/cum
g -Gravity acceleration, mtr/s2
Q - Flow rate in cum/s
H - Total head in mtr

Hr - Height of the pumped medium lift, mtr
Hl - Head loss, mtr

How to calculate the Pump head?

Pump head can be find out by following equation:

Head calculation:

H = (p2-p1)/(Rho x g) + Hг + Hl

H – Head, m

p1 – Intake tank pressure, Pa

p2 – Receiving tank pressure, Pa

Rho – Density of the pumped medium, kg/cum

g – Gravity acceleration, mtr/s2

Hr – Height of the pumped medium lift, mtr

Hl– Head loss, mtr