Moment of Inertia Calculator

Moment of inertia measures how hard it is to change a rotating object's spin — the rotational analog of mass.

The math behind it

Each shape has a standard coefficient: I = k·m·r² (or k·m·L² for rods). More mass farther from the axis means a larger moment of inertia.

Worked Example

Solid cylinder, m = 2, r = 0.5 → I = ½·2·0.25 = 0.25.

Frequently Asked Questions