Moment of Inertia formula:
    I = m × r²

where:

   I: Moment of Inertia, in kg.m^2
   r: Distance from the Rotating Axis, in m
   m: Mass of the Object, in Kg

The moment of inertia calculates the rotational inertia of an object rotating around a given axis. It represents how difficult it overcomed to change its angular motion about that axis. Moment of inertia of a same object will change against different axis. The more far away from the axis, the more moment of inertia the object has.