paper: Simple Motor Calculator

[Ether]

The updated version will allow you to enter a desired motor power, and it will then calculate the rpm range, the torque range, and the current range over which the motor will deliver at least that much power.

Also, if there is some reason why you want to always operate the motor at or above a certain efficiency, you can enter the desired efficiency and it will calculate the rpm range, the torque range, the current range over which the motor will operate at an efficiency equal to or greater than the entered number.