What is the typical/average percentage of loss of energy in transfers from one trophic level to the next?

The typical or average percentage of loss of energy in transfers from one trophic level to the next is approximately 10%. This means that only about 10% of the energy from one trophic level is transferred to the next level, while the remaining 90% is lost in the form of heat or is used for metabolic processes. This is known as the 10% rule and it is a fundamental concept in ecological energetics.