Moment of inertia from a physics point of view is basically a quantitative measure of the rotational inertia or the angular mass of a body. In simple terms, it is the opposition that the body exhibits to the change in rotation about an axis which may further be internal or external. The moment of inertia (I) is mostly specified based on the distribution of mass in the body with respect to the axis of rotation.
SI Unit of Moment Of Inertia
An important thing to be noted here is that there are usually two kinds of moment of inertia. They are, mass moment of inertia and area moment of inertia. So these are further expressed in different units. If we consider the mass moment of inertia which is for rotational dynamics then the unit is kg-m2. For area moment of inertia, the unit is m4.
Conversion Between Moment of Inertia Units