How to convert the torque and power of Stepper motor

Stepper motor generally in the larger range of speed use, its power is changed, generally only stepper motor torque to measure.

The torque and power of the stepping motor are as follows:

P=.M =2.N/60 P=2 nM/60 pi pi.

Its P is watts for power units,

Rate of angular velocity per second,

Unit of arc,

N rpm.,

M as the torque unit for Newton.

P=2 PI fM/400 (half step)

Where f is a second pulse number (PPS)