How to Convert HP to Torque ?

Torque represents a twisting force that causes an object to rotate, such as the force required to tighten a screw or to spin a wheel. In the imperial system of measures, which is used in the United States, torque is measured in foot-pounds. Usually torque refers to circular rotation, such as a spinning gear, but the rotation does not always have to be circular. To convert HP to torque, you also need to know the engine's number of rotations per minute.

* Look up the horsepower of your device in the owner's manual. This can be a car motor, water pump or any other mechanical device.

* Multiply the horsepower by the RPM at which your engine is turning, as in the following formula: HP*RPM. RPM stands for rotations per minute, and is shown on a tachometer, such as the one in a car. For example, if you have a 200 HP engine running at 2,500 RPM, you would multiply 200 by 2,500 to get 500,000.

* Divide the result from step 2 by 5,252 to calculate torque in foot-pounds.

The conversion factor of 5,252 is derived from one horsepower being equal to 550 foot-pounds per second; you have to multiply that number by 60 to convert from seconds to minutes (RPM means rotations per minute) and divide the result by 6.28, because there are 2π radians in a circle.

Finishing our example from the previous step, you would divide 500,000 by 5,252 to find the torque produced by a 200 HP engine running at 2,500 RPM, which equals about 95.2 foot-pounds of torque.