What is the average age of the middle manager or the range of years of experience he must have? Does age is fair enough to evaluate the employees by?

30 -35 for Middle management (Manager);35 -45 Senior management (Sr. Manager, Director);45 -55 Executive Management (VP, Sr. VP, EVP or CEO).. 

From what I have seen, the range  (35 -45) seems to be ideal age for middle management positions with anywhere between10-15  years experience .... 

It also depends on the type of industry, the discipline, and the environment and may vary from one case to another case accordingly !

My opinion. the range is35 -45 is the a a good age for middel manager. 

from25, and I not believe of age to evaluate some one.

For a Middle Management position, the age of35 to50 is ideal. For Higher Management,50 to65 is ideal.

A person cannot be evaluated for his competencies based upon age alone as there are several other factors that have to be evaluated. However, I recommend the Age Slabs stated above and any deviation from this is not advisable.     

I feel28-38 is the right age to gear-up for Top Management position.

The average age of a middle manager is between33 and38 years.

Age is an evaluating factor for some types of jobs. A pilot friend on mine told me once (to fly this bird (a Boieng747) you have to have gray hair).

30 TO45

from30 to40 years old

In my opinion age should not be a factor. Average age for middle management position is 32 to 37 years with a minimum of 7 to 10 years of experience.