Motor Torque Calculator
Torque is the twisting force a motor puts on its shaft. Enter the motor's power and its speed, and this gives the torque in both metric and US units.
- Free
- Works offline after your first visit
- Saves on this device
- No sign-up
- Updated
How it works
Torque equals power times 60, divided by two times pi times the speed in revolutions per minute. That gives newton-metres.
Power is converted to watts first, so horsepower and kilowatts give the same answer. The pound-feet figure is the newton-metre figure divided by 1.3558.
Worked example
A 5 hp motor at 1,750 rpm makes about 20.3 newton-metres of torque, or 15 pound-feet.
Questions
Does a bigger motor always have more torque?
Not on its own. Torque depends on power and speed together. At the same power, a slower motor gives more torque.
Is this the torque under load?
It is the torque at the power and speed you enter. Real torque changes with the load, and the motor's nameplate or data sheet lists the figures for your model.
Why does speed matter so much?
For the same power, fewer turns per minute means each turn carries more twisting force.
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