Machine Efficiency Calculator

About this calculator

This calculator computes mechanical efficiency, η = (output work or energy / input work or energy) × 100, the percentage of energy put into a machine that actually shows up as useful output rather than being lost — mostly to friction, heat, and vibration. Because no real machine is perfectly efficient, η is always below 100%, and the gap between input and output is a direct measure of how much energy the machine wastes.

Mechanical engineers use this figure to compare motors, engines, gearboxes, and pulley systems, and to decide when a maintenance issue (like a worn bearing) is dragging performance down. It's also a standard homework calculation in physics and engineering courses covering work, energy, and simple machines, where students measure input and output work directly to find how a real system compares to an ideal one.