Moment of Inertia Calculator

Enter value and click on calculate. Result will be displayed.
Enter the mass of hollow material (M) :
lbm,kg
Distance between axis and rotation (D) :
ft,m
Result:
Moment of inertia :

A Moment of Inertia Calculator is a tool that helps you calculate the moment of inertia (also called the rotational inertia) of an object. The moment of inertia is a measure of an object's resistance to changes in its rotational motion about a specific axis. It's the rotational analog to mass in linear motion.

Why use a Moment of Inertia Calculator?

The moment of inertia is essential in rotational dynamics, which deals with objects that rotate or spin. It's used to predict how much torque is needed to change an object's rotational speed. The moment of inertia depends on both the mass of the object and how that mass is distributed relative to the axis of rotation. This calculator is helpful for quickly determining the moment of inertia of different shapes and objects in physics or engineering problems.

How does a Moment of Inertia Calculator work?

The moment of inertia (II I) of an object is calculated using different formulas depending on its shape and axis of rotation. For example:

  1. For a solid sphere rotating about its center:
  2. For a solid cylinder rotating about its center:
  3. For a thin rod rotating about its center:

where:

  • m is the mass of the object,
  • r is the radius (if applicable),
  • L is the length (for a rod),
  • I is the moment of inertia.

The calculator helps you input the mass, shape, and axis of rotation to compute the moment of inertia automatically.

When to use a Moment of Inertia Calculator?

  • Rotational dynamics problems: When studying or solving problems related to rotational motion (like angular acceleration or torque).
  • Engineering applications: In mechanical engineering, for analyzing the rotational behavior of gears, wheels, and other rotating parts.
  • Physics studies: In topics like conservation of angular momentum and rotational energy.