Efficiency Calculator

Calculate how effectively a machine converts input energy into useful work

η = (WO ÷ WI) × 100%

What is Efficiency?

The ratio of useful work output to total work input, expressed as a percentage.

Practical Range

Real machines are always below 100% efficient due to friction, heat, and sound losses.

How to Improve

Reduce friction with lubrication, use lighter components, and minimize moving parts.

Formula

Efficiency of a machine

η = (Work Output ÷ Work Input) × 100

η — eta — Greek symbol for efficiency

WOWork OutputJ
WIWork InputJ
ηEfficiency%

Enter Values

The useful energy produced by the machine (Load × Distance)

J

The total energy supplied to the machine (Effort × Distance)

J

Work Output must be less than or equal to Work Input — a machine cannot produce more energy than it receives.

No result yet

Enter the work output and work input values on the left, then press Calculate Efficiency to see your result and visual gauge.

Example Problems

Try these values to see how the calculator works

Pulley System

Moderate
Work Output750 J
Work Input1000 J
Efficiency75%

Class 1 Lever

High
Work Output920 J
Work Input1000 J
Efficiency92%

Inclined Plane

Low
Work Output380 J
Work Input1000 J
Efficiency38%