Moment of Inertia Calculator
Calculate moment of inertia for common shapes. Find rotational inertia for disks, spheres, rods, and more.
Parallel Axis Theorem
Moment of Inertia
0.125kg*m^2
About Center of Mass
Formula for Solid Disk
I = (1/2)MR^2

Solid disk rotating about central axis perpendicular to disk

Shape Visualization

Common Moment of Inertia Formulas

Moment of inertia (rotational inertia) is the rotational analog of mass. It quantifies the resistance of an object to rotational acceleration about an axis.

Solid Disk: I = (1/2)MR^2
Solid Sphere: I = (2/5)MR^2
Thin Rod (center): I = (1/12)ML^2
Ring/Hoop: I = MR^2
Rectangular Plate: I = (1/12)M(L^2 + W^2)
Parallel Axis Theorem: I = I_cm + Md^2

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