Hydraulic Motor Torque Calculator

⚙️ Hydraulic Motor Torque Calculator

Calculate actual output torque, flow rate, efficiency, and power for hydraulic motors

Quick Presets
Unit System
Motor Parameters
PSI
in³/rev
Typical: 90–98%
Typical: 88–96%
Used for flow & power calculation
✅ Calculation Results
Actual Output Torque
Overall Efficiency
Required Flow Rate
Output Power
📊 Calculation Breakdown
Theoretical Torque
Mechanical Efficiency Loss
Volumetric Efficiency
Theoretical Flow Rate
Actual Flow Rate
Input Power
Output Power
Torque Tip: Higher displacement = more torque at the same pressure, but lower maximum speed.
Heat Tip: Mechanical efficiency losses appear as heat — ensure adequate cooling for your hydraulic system.
⚠️ Safety Note: Never exceed rated pressure or speed. Hydraulic systems can store dangerous energy — always depressurize before maintenance.
Torque Output Reference Table (Imperial, 92% Mech. Eff.)
Displacement1000 PSI2000 PSI3000 PSI
0.5 in³/rev73 in-lb / 6.1 ft-lb146 in-lb / 12.2 ft-lb220 in-lb / 18.3 ft-lb
1.5 in³/rev220 in-lb / 18.3 ft-lb439 in-lb / 36.6 ft-lb659 in-lb / 54.9 ft-lb
3 in³/rev439 in-lb / 36.6 ft-lb878 in-lb / 73.2 ft-lb1317 in-lb / 109.8 ft-lb
10 in³/rev1464 in-lb / 122 ft-lb2928 in-lb / 244 ft-lb4392 in-lb / 366 ft-lb
20 in³/rev2928 in-lb / 244 ft-lb5856 in-lb / 488 ft-lb8784 in-lb / 732 ft-lb
50 in³/rev7320 in-lb / 610 ft-lb14639 in-lb / 1220 ft-lb21959 in-lb / 1830 ft-lb
Efficiency Reference
90–98%
Volumetric Efficiency
88–96%
Mechanical Efficiency
80–94%
Overall Efficiency
6–20%
Power Lost as Heat
Hydraulic Motor Types Comparison
Motor TypeDisplacement RangeEfficiencyBest Use
Gear Motor0.1–100 in³/rev85–90%General purpose, low cost
Vane Motor0.5–50 in³/rev88–92%Moderate torque, smooth operation
Piston Motor0.2–200 in³/rev92–97%High performance, variable speed
Orbit (Gerotor)5–500 in³/rev85–93%Low speed, high torque applications
Flow Rate vs Motor Speed (Imperial, 95% Vol. Eff.)
Displacement500 RPM1000 RPM2000 RPM3000 RPM
1.5 in³/rev3.4 GPM6.8 GPM13.7 GPM20.5 GPM
3 in³/rev6.8 GPM13.7 GPM27.3 GPM41.0 GPM
10 in³/rev22.8 GPM45.5 GPM91.1 GPM136.6 GPM
20 in³/rev45.5 GPM91.1 GPM182.2 GPM273.3 GPM

Hydraulic motors work as rotary drives that change hydraulic energy to mechanical torque. They use the pressure and flow that a hydraulic pump provides to convert that energy into spinning that helps move many kinds of machines.

torque has a truly key role for hydraulic motors. It decides how well they can do various jobs. Enough torque is needed to beat loads, start machines up and keep stable spinning speed.

How Torque Affects Hydraulic Motors

Without the right amount of torque, a motor simply can not do its task well.

Many kinds of hydraulic motors exist. One common type is those with low speed and high torque. One finds also motors for high speed, wheel motors, rotary dirves and mixes of even pump with motor.

Some of them have high power density, for instance axial piston motors, while others are built with high torque density, like orbit motors or radial piston motors.

The series BMMa represent one example of compact, high-performance design with low speed and high torque. It uses a valve to distribute the flow and works in parallel or serial systems.

To estimate the created torque of a hydraulic motor, one uses a simple formula. One takes the value in PSI, multiplies it by the shift of the motor, then divides by twice pi. That results in torque measured in inch-pounds.

For instance, 3000 psi multiplied by 0.25 cubic inches for one revolution, divided by 6.283, gives around 119.4 inch-pounds, witch is about 13.5 Nm.

The stall torque of hydraulic motors depends on their volume shift per revolution and on the pressure in the system. In hydraulics, one can turn load into pressure. Torque forms a link between shift per revolution and resistance of the load.

Also the efficiency of the motor is important. In hydraulic motors, efficiency normally sits between 0.85 and 0.95. A program calculator helps engineers quickly compute the output of torque, spinning speed and power based on shift, pressure, flow rate and efficiency.

torque also affects the flow rate in a hydraulic system. The torque of the motor decides how well the pump will beat the resistance of the system and will keep the flow. In a system with fixed shift, when the load grows, the electric motor that moves the pump slows a bit and then takes more power.

That causes the motor to make less torque at bigger loads.

It is important to choose a motor size right for the task. If the motor lacks enough shift, it could stop because of lack of torque before reaching full ability. Making the hydraulic pump bigger to match the available horsepower can let the system reach max pressure, but the tradeoff is slower spinning.

Torque, pull andhorsepower all add to the movement of motors and are closely tied one to the other in final drive uses.

Hydraulic Motor Torque Calculator

Author

  • Thomas Martinez

    Hi, I am Thomas Martinez, the owner of ToolCroze.com! As a passionate DIY enthusiast and a firm believer in the power of quality tools, I created this platform to share my knowledge and experiences with fellow craftsmen and handywomen alike.

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