Work out mechanical efficiency instantly with clear inputs, formula shown and shareable results.
Mechanical efficiency is useful output over total input, expressed as a percentage. 7.5 kW delivered from 9.2 kW supplied is 81.5% efficient, with 1.7 kW going into friction, windage and heat. Efficiency can never exceed 100%, and a chain of components multiplies their individual efficiencies together.
Efficiency
efficiency = 100 x output / input
Loss
loss = input - output
Spur gear pairs reach 97-99%, V-belts 93-97%, worm drives only 40-90%, and a whole gearbox is the product of its stages.
No. A figure above 100 means the input has been measured wrongly or some energy source has been overlooked.