Inputs
Flow Q, pressure difference Δp, pump and motor efficiency and speed.
Pressure and flow are separate power levers: pressure creates force, flow creates speed. Efficiencies explain the difference between hydraulic output and electrical input.
Hydraulics · drive
Hydraulic Pump Power Calculator
Calculate hydraulic power, pump shaft power, electrical input power and torque from pressure and flow rate.
ISO4413
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Power result
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Set the inputs and run the calculation.
Inputs and method
Hydraulic pump power
Convert flow and pressure difference into hydraulic, shaft and electrical power.
Calculation
Pₕ = Δp·Q; shaft power = Pₕ/ηₚ; electrical power = Pₕ/(ηₚηₘ). Torque follows from power and angular speed.
Example
20 l/min at 100 bar is about 3.33 kW hydraulic power; at 80% pump efficiency shaft power is 4.17 kW.
Sources and limits: Hydraulic power identity; add actual maps, losses and thermal limits.
Hydraulic pump power in detail
Convert flow and pressure difference into hydraulic, shaft and electrical power.
What does this quantity describe?
Hydraulic calculations link pressure difference, effective area and flow. Pressure determines force, flow determines speed, while line losses and efficiency reduce ideal values.
Formula and variables
Pₕ = Δp·Q; shaft power = Pₕ/ηₚ; electrical power = Pₕ/(ηₚηₘ). Torque follows from power and angular speed.
Choose the inputs correctly
Flow Q, pressure difference Δp, pump and motor efficiency and speed. Pressure and flow are separate power levers: pressure creates force, flow creates speed. Efficiencies explain the difference between hydraulic output and electrical input.
How to use the calculator
Enter flow, pressure difference and pump and (if applicable) motor efficiency. The calculator returns hydraulic power, required shaft power and, where needed, electrical input power.
Worked example
20 l/min at 100 bar is about 3.33 kW hydraulic power; at 80% pump efficiency shaft power is 4.17 kW.
Understand the result and units
Pressure and flow are separate power levers: pressure creates force, flow creates speed. Efficiencies explain the difference between hydraulic output and electrical input. The result is a pre-sizing point. Higher pressure raises cylinder force; more flow raises speed but usually also increases losses and heat.
Flow in l/min, pressure difference in bar, power in kW, speed in rpm.
Typical applications
Sizing the drive motor for a hydraulic pump at known flow and operating pressure, or estimating the electrical connection power of a hydraulic power unit.
Assumptions, limits and common mistakes
Hydraulic power identity; add actual maps, losses and thermal limits.
Common mistake: Don't equate hydraulic power with required shaft power – pump efficiency is practically always below 100%, so the drive machine must supply more power than is hydraulically used. For electrical input power, also don't forget motor efficiency.
Frequently asked questions
Why do hydraulic power and shaft power differ?
Hydraulic power Δp·Q describes power used in the fluid; friction and internal pump losses require higher mechanical shaft power to deliver that useful power.
How are torque and power on the pump shaft related?
Torque follows from shaft power divided by angular speed (2π·n/60); at constant power, required torque falls as speed rises.
Is this calculator enough for motor selection?
It gives the ideal base power. Starting torque, the real motor's performance map, load peaks and safety margins must be additionally checked.
Hydraulic Pump Power Calculator
Determine drive power from pressure and flow with separate pump and motor efficiencies.
Additional checks
Results are preliminary engineering estimates. Component approval, safety functions, material, fatigue, installation checks and the complete system assessment remain separate.