Parallel Axis Theorem

If the rotation axis does not traverse the center of mass of the solid body with the mass $M$, the moment of inertia can be calculated according to: $$\boxed{I = I_\mathrm{S} + Md^2}$$ where $I_\mathrm{S}$ is the moment of inertia of the center related to the center of mass and $d$ the distance between the center of mass and the rotation axis.\par