Moment of Inertia Calculator

Moment of Inertia Calculator

Moment of Inertia
Mass of object
Distance from Rotating axis


Moment of Inertia refers to a measure of an object’s resistance to change its rotation. Moment of Inertia of a body depends on the distribution of mass in the body with respect to the axis of rotation. The moment of inertia is measured as the inertia of a rotating body with respect to its rotation. 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. Moment of Inertia is always relative to a given axis. The more far away from the axis, the more moment of inertia the object has.


For a point mass the Moment of Inertia is the mass times the square of perpendicular distance to the rotation reference axis and can be given as :

I(kg.m²) = m(kg) * r²( m²)

I = moment of inertia
m = mass of object
r = distance between axis and rotation object

For Example:

Ques: Calculate the Moment of Inertia for the rotating object if mass of hollow material is 5kg and the distance between axis and rotation is 10 m?

Sol. :

I = m * r²

I = 5(kg) * 10²( m²)

I = 5 * 100

I = 500 kg.m²

Moment of Inertia is 500 kg.m²


The standard unit of measurement for moment of inertia is kg.m²