Power of the electric motor is related to its torque and shaft speed according to the following formula:

**P = M x w**

**P** is power of the motor in **Watts (W)**

**M** is torque on the motor shaft in **Newton meters (Nm)**

**w** is angular speed of the motor shaft in **radians per second (rad/s)**

In order to convert motor speed from revolutions per minute**(RPM)** to radians per second**(rad/s)**use the following formula:

rad/s = [60/(2 x 3.14)] x RPM

For example: 1500 RPM = [60/(2 x 3.14)] x 1500 = 14331.2 rad/s

If rated power of the motor is 7.5kW and its rated speed is 1500RPM, its shaft torque is:

M = 7500 / {[60/(2 x 3.14)] x 1500} = 7500 / 14331.2 = 0.523 Nm