Efficiency Calculator

Efficiency is the ratio of useful energy output to total energy input, expressed as a percentage. It measures how effectively a device converts input energy into useful work. A 70% efficient car engine converts 70% of fuel energy into motion, with 30% lost as heat.

No, efficiency cannot exceed 100% as this would violate the law of conservation of energy. You cannot get more energy out than you put in. Any claim of over-100% efficiency indicates a measurement error or misunderstanding of what's being measured.

All real machines lose some energy to friction, heat, sound, or other forms that aren't useful work. Even the best machines have some resistance, deformation, or other energy-dissipating processes. Superconductors can approach 100% for electrical transmission, but mechanical machines always have losses.

Efficiency is a ratio (output/input) showing how well energy is converted, while power is the rate of energy transfer. A device can be high-power but low-efficiency (wasting lots of energy quickly) or low-power but high-efficiency (using little energy effectively).

Improve efficiency by reducing energy losses: use better lubrication to reduce friction, improve insulation to reduce heat loss, optimize designs to minimize resistance, use better materials, and maintain equipment properly. Small improvements in efficiency can lead to significant energy and cost savings.

Electric motors: 85-95%, gasoline engines: 20-30%, diesel engines: 30-45%, LED bulbs: 20-30%, incandescent bulbs: 5%, power plants: 30-40%, bicycles: 90-98%, photovoltaic cells: 15-25%. The wide range shows how different technologies convert energy with varying effectiveness.