Calculate the energy efficiency of any machine or process.
Energy or Work
Efficiency Results
Enter input and output values
About this calculator
Quick Reference
OutputUseful work achieved
InputTotal energy consumed
LossesHeat, sound, friction, etc.
Overview
Efficiency is a measure of how much of the energy put into a system is actually converted into useful work or output, rather than being lost as heat or sound.
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Pro Tips
Efficiency = (Useful Output / Total Input) × 100%.
Efficiency can never be greater than 100% (due to the Law of Conservation of Energy).
Make sure both 'In' and 'Out' values are in the same units (e.g., Joules, Watts, or HP).
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Fun Facts
"Modern LED bulbs are about 80-90% efficient, compared to only 5% for old incandescent bulbs."
"Most internal combustion engines are only about 20-35% efficient."
"Electric motors are highly efficient, often exceeding 90%."
