formula.expert

Thermal Efficiency

η=WQh\eta = \frac{W}{Q_h}

Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!

Learning zone

Thermal efficiency is the fraction of heat input a machine turns into useful work — η = 0.25 means a quarter of the fuel's energy moves the car while the rest leaves as hot exhaust and radiator heat. As a ratio of two energies it is dimensionless, always between 0 and 1, and usually quoted as a percentage.

Thermal Efficiency
η=WQh\eta = \frac{W}{Q_h}
Where
  • η\eta= Efficiency
  • WW= Useful work output
  • QhQ_h= Heat input
Missing one of these? Work it out first, then come back