About the Pump Head Calculator
What is the Pump Head Calculator?
A pump must lift water through the static height and overcome friction in the pipes. This pump head calculator adds suction lift, delivery height and friction (Hazen–Williams) to give the total dynamic head.
It then works out the power the pump needs and suggests a standard motor size in HP, as used for Indian domestic and agricultural pumps.
How to use the Pump Head Calculator
- Required Flow (m³/h) (sample: 10)
- Suction Lift – water level to pump (m) (sample: 3)
- Delivery Height – pump to outlet (m) (sample: 15)
- Total Pipe Length (m) (sample: 60)
- Pipe Inner Diameter (mm) (sample: 50)
- Pipe Material (sample: PVC / HDPE (C = 150))
- Allowance for Fittings (% of pipe loss) (sample: 15)
- Pump Efficiency (%) (sample: 60)
- Press Calculate Pump Head (results also refresh as you type). The result card shows the Total Dynamic Head, along with Static head, Friction head incl. fittings, Pump input power and In horsepower.
Formula used
Total head = Suction lift + Delivery height + Friction head
- Friction (Hazen–Williams) = 10.67 × L × Q^1.852 ÷ (C^1.852 × D^4.87)
- Power (kW) = ρ × g × Q × H ÷ efficiency ÷ 1,000
Suction lift for surface pumps is practically limited to about 6–7 m.
Worked example
These are the sample values already filled in the calculator above, and the result it returns for them:
| Input | Sample value |
|---|---|
| Required Flow (m³/h) | 10 |
| Suction Lift – water level to pump (m) | 3 |
| Delivery Height – pump to outlet (m) | 15 |
| Total Pipe Length (m) | 60 |
| Pipe Inner Diameter (mm) | 50 |
| Pipe Material | PVC / HDPE (C = 150) |
| Allowance for Fittings (% of pipe loss) | 15 |
| Pump Efficiency (%) | 60 |
| Result | Value |
|---|---|
| Total Dynamic Head | 20.75 m |
| Static head | 18 m |
| Friction head incl. fittings | 2.75 m |
| Pump input power | 0.94 kW |
| In horsepower | 1.26 HP |
| Suggested motor (10% margin) | 1.5 HP |
| Pipe velocity | 1.41 m/s |
Tips for using the Pump Head Calculator
- Match the pump to the duty point on its curve, not just the motor HP.
- Oversized suction pipes reduce the risk of cavitation.