Enter the angular moment and the angular velocity into the calculator to determine the rotational inertia.

- Angular Momentum Calculator
- Angular Velocity Calculator
- Mass Moment of Inertia Calculator (Point Mass)

## Rotational Inertia Formula

The following formula is used to calculate a rotational inertia.

I = L / w

- Where I is the rotational inertia (kg*m^2)
- L is the angular momentum (kg*m^2*s^-1)
- w is the angular velocity (rad/s)

## Rotational Inertia Definition

Rotational inertia is defined as the total resistance to rotational movement about a radius.

## Rotational Inertia Example

How to calculate rotational inertia.

**First, determine the angular moment.**For this example, we will say the rotating object has an angular moment of 20 (kg*m^2*s^-1).

**Next, determine the angular velocity.**For this example, the angular velocity will be 25 rad/s.

**Finally, calculate the angular inertia.**Using the formula we find the inertia to be 20/25 = .80.

## FAQ

**What is rotational inertia?**

Rotational inertia is the resistance of an object to rotate about an object.