Finding Full-load Torque

Full-load torque is the force needed to produce the rated power at maximum RPM of a motor. The amount of torque a motor produces at rated power and full speed can be found by using a horsepower-to-torque conversion chart.

To calculate motor full-load torque:

T =( HP x 5252)/rpm


T = torque (in lb-ft)
HP = horsepower
5252 = constant
rpm = revolutions per minute

• Example: What is the Full-load torque of a 30HP motor operating at 1725 rpm?

T = ( HP x 5252 ) /rpm

T = (30 x 5252)/1725

T = 157,560 / 1725

T = 91.34 lb-ft