This calculator finds the airgap of a brushless outrunner-motor based on the size of motor together with magnet width and thickness. Just enter your data and compute. Negative number means you have too thick magnets. An airgap of 0.1mm will give high torque, while less would be inconvenient.
(You can enter data in any measure you like, as long as you use same on all fields.)



Airgap calculator for outrunner motors:
Your parts: Stator outer diameter: 
Bell inner diameter: 
Magnet width:
Magnet thickness:
Resulting airgap: