Hydraulic Power Calculator

Enter flow, pressure, density, head, and efficiency values. Get power, losses, and converted outputs instantly. Download reports and inspect performance curves with clear graphs.

Calculator Input Form

Pressure mode uses P = Q × Δp. Head mode uses P = ρ × g × Q × H. Both methods also estimate shaft power, electrical input, losses, energy, and cost.
Enter the working flow rate.
Select the unit for flow.
Used when pressure mode is selected.
Common pump and hydraulic pressure units.
Used when head mode is selected.
Head can be entered in meters or feet.
Pump or system efficiency.
Motor or drive efficiency.
Water is near 998 to 1000 kg/m³.
Use 9.81 unless a different value is needed.
Used to estimate daily energy use.
Enter your local electricity tariff.

Example Data Table

Case Method Flow Pressure / Head Efficiency Hydraulic Power Input Power
1 Pressure 120 L/min 150 bar 85% / 92% 30.00 kW 38.36 kW
2 Pressure 60 L/min 80 bar 78% / 90% 8.00 kW 11.40 kW
3 Head 45 m³/h 42 m head 80% / 93% 5.14 kW 6.91 kW
4 Head 75 m³/h 28 m head 82% / 94% 5.71 kW 7.40 kW
5 Pressure 200 gpm 180 psi 88% / 95% 15.65 kW 18.73 kW

Formula Used

Pressure method:
Hydraulic Power (W) = Flow Rate (m³/s) × Pressure Differential (Pa)
Head method:
Hydraulic Power (W) = Density (kg/m³) × Gravity (m/s²) × Flow Rate (m³/s) × Head (m)
Required shaft power:
Shaft Power = Hydraulic Power ÷ Hydraulic Efficiency
Electrical input power:
Electrical Input = Shaft Power ÷ Drive Efficiency
Energy and cost:
Daily Energy (kWh) = Electrical Input (kW) × Operating Hours
Daily Cost = Daily Energy × Energy Rate

Use the pressure method when pressure differential is already known. Use the head method when system head is easier to measure. Both approaches describe the same hydraulic output energy transfer under different input formats.

How to Use This Calculator

  1. Select whether you want to calculate from pressure differential or hydraulic head.
  2. Enter the flow rate and choose its unit.
  3. Enter either pressure differential or head, depending on the selected method.
  4. Provide hydraulic efficiency and drive efficiency values.
  5. Enter fluid density, gravity, operating hours, and energy rate.
  6. Press Calculate Hydraulic Power to display the results above the form.
  7. Review the power summary cards and the Plotly graph.
  8. Use the CSV or PDF buttons to export the calculation report.

Frequently Asked Questions

1. What is hydraulic power?

Hydraulic power is the useful power transferred by a moving fluid under pressure or head. It shows how much energy per second the fluid delivers to a hydraulic system or process.

2. When should I use pressure instead of head?

Use pressure when you directly know the pressure difference across the system or pump. Use head when the system is described by elevation, static head, or total dynamic head measurements.

3. Why does the calculator ask for fluid density?

Density is required for head-based calculations and for converting pressure to equivalent head. Different fluids transfer energy differently, so density affects the relationship between pressure and head.

4. What is the difference between hydraulic power and shaft power?

Hydraulic power is the useful output carried by the fluid. Shaft power is the mechanical power required before hydraulic losses are considered, so it is always greater when efficiency is below 100%.

5. Why is electrical input power higher than shaft power?

The motor or drive is not perfectly efficient. Electrical input power includes the extra energy needed to overcome motor, drive, and related conversion losses before mechanical shaft power reaches the pump.

6. Can I use this calculator for water pumps?

Yes. It works well for water pumping, hydraulic machinery, industrial fluid systems, and many engineering checks. Just enter realistic density, efficiency, and operating values for your application.

7. What units does this calculator support?

It supports multiple flow units, pressure units, and head units. Results are also shown in common engineering forms such as kW, horsepower, bar, psi, meters, and feet.

8. How accurate are the energy cost estimates?

The cost estimate is useful for planning and comparison. Actual cost can differ because of variable loading, duty cycles, changing tariffs, temperature effects, maintenance condition, and part-load motor performance.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.