Torque is a measuring of rotational force. In engines it refers to the pressure the crankshaft puts on the pistons. Engine torque changes depending on the revolutions per minute (RPM) of the engine. An engine running at low RPM will have less torque than an engine running at high RPM. An engine's torque is always expressed at a set number of RPM. Along with horsepower, torque is a traditional measure of an engine's power.
Enter the engine's horsepower in your calculator. Press the "*" or "X" key for multiply.
Enter "5252" on your calculator, then press the "=" key. 5252 is the mathematical constant in the formula for calculating torque. Torque equals the horsepower multiplied by 5252. The result is then divided by the RPM or revolutions per minute.
Press the "/" key, which is the division key. Enter the RPM, then press the "=" key. The result is the torque in lb-ft., which is foot-pound or pound-foot, the traditional unit of measurement for torque.
