Pump Power Calculator
Enter flow rate, fluid head, density, and pump efficiency to get hydraulic and shaft power in metric or imperial units.
Use the Pump Power Calculator
Pump Inputs
75%
1%
100%
Enter pump parameters and click Calculate Power.
Hydraulic Power (P_hyd)
Useful power to fluid—
kilowatts (kW)
—
horsepower (hp)
Shaft Power (P_shaft)
Power needed from motor—
kilowatts (kW)
—
horsepower (hp)
Calculation Summary
Formula: Phyd = ρ × g × Q × H | Pshaft = Phyd / η
Common Fluid Densities
| Fluid | kg/m³ | lb/ft³ |
|---|---|---|
| Fresh Water (15°C) | 999 | 62.4 |
| Seawater (15°C) | 1025 | 64.0 |
| Light Oil | 850 | 53.1 |
| Diesel Fuel | 835 | 52.1 |
Summary
Enter flow rate, fluid head, density, and pump efficiency to get hydraulic and shaft power in metric or imperial units.
How it works
- Select your preferred unit system (SI or Imperial).
- Enter the volumetric flow rate (m³/s or GPM).
- Enter the total differential head across the pump (m or ft).
- Enter the fluid density (kg/m³ or lb/ft³) — water defaults are pre-filled.
- Set pump efficiency as a percentage (0–100).
- The tool computes hydraulic power (P_hyd = ρ × g × Q × H) and shaft power (P_shaft = P_hyd / η) instantly.
Use cases
- Size electric motors for industrial centrifugal pumps.
- Calculate energy consumption in water distribution systems.
- Verify pump selection for irrigation and agricultural systems.
- Determine shaft power for oil and chemical process pumps.
- Compare hydraulic power across different operating points.
- Estimate energy cost of pumping operations.
Frequently Asked Questions
Last updated: 2026-09-22 ·
Reviewed by Nham Vu