What percentage of protein do chickens need in their diets?

[MyChickenCookie]

I was once told that too much protein in a hen's diet can produce huge eggs that cause harm to the hen when she is laying them. Ever since I have been worried ever since that I would feed my girls too much protein and cause them pain. What percentage of protein do chickens need in their diets?

 

[waddles99]

Most layer feeds are 16%