When to use this calculator
Estimate input power for a fluid flow and head scenario. Does not size electrical protection or include a separate motor efficiency unless reflected in the entered overall efficiency.
Explore the fluids & flow calculators for other questions in this topic. For a related calculation, use the Hydrostatic Pressure Calculator: Find gauge pressure caused by a liquid column.
PUTTING IT INTO PRACTICE
Hydraulic Pump Power: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Fluid density (kg/m³) | 1,000 |
| Gravity (m/s²) | 10 |
| Flow (m³/s) | 0.01 |
| Head increase (m) | 20 |
| Pump efficiency (%) | 80 |
| Result | 2,500 W |
- Check the input labels and enter the example values above.
- Apply the relationship: Input power = density × gravity × flow × head/efficiency.
- The result is 2,500 W, rounded for display.
How to interpret your result
Does not size electrical protection or include a separate motor efficiency unless reflected in the entered overall efficiency.
Use the fluid properties at the relevant conditions. Gauge pressure is measured relative to a reference and differs from absolute pressure. Average flow velocity and characteristic length must match the geometry being modelled.
Frequently asked questions
Should hydrostatic pressure be added to atmospheric pressure?
Add the surface absolute pressure when an absolute result is needed. The basic liquid-column calculation alone gives the pressure increase with depth.
When is the hydraulic pump power calculator useful?
Estimate input power for a fluid flow and head scenario. Does not size electrical protection or include a separate motor efficiency unless reflected in the entered overall efficiency.
How do I use the hydraulic pump power calculator?
Enter fluid density (kg/m³), gravity (m/s²), flow (m³/s), head increase (m), pump efficiency (%). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Input power = density × gravity × flow × head/efficiency.
What should I check before using the result?
Does not size electrical protection or include a separate motor efficiency unless reflected in the entered overall efficiency.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see OpenStax: fluids, density and pressure ↗. This is a topic reference, not an external review or endorsement of this tool.
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