Rotational Kinetic Energy Calculator

About this calculator

This calculator finds rotational kinetic energy using KE = ½·I·ω², the rotational analogue of the familiar ½·m·v² formula for straight-line motion. Here, moment of inertia I (in kg·m²) replaces mass and captures how an object's mass is distributed relative to its rotation axis — a solid disk, a hollow ring, and a sphere all have different I formulas for the same mass and radius — while angular velocity ω (in radians per second) replaces linear velocity.

Mechanical and automotive engineers use this to size flywheels that store energy smoothly in engines and machinery, to analyze spinning components like turbine rotors, gears, and crankshafts, and to model wheel and wind-turbine blade dynamics; physics students use it to connect linear and rotational mechanics in coursework. Enter the moment of inertia and angular velocity to get the rotational kinetic energy.