The ratio is 1 rooster to 10 hens. Alot depends on cerumstances if one is breeding one does the 1 to 3 ratio. If in a flock 1 to 10 ratio. If the chickens are free ranging and not in a pen or enclosure then it will vary depending on the roosters flock. If you re raising meat chickens that are penned, and by the sound of it that is what you are doing. It will not matter since they are dead by 12 weeks old. If they are in a pen or enclosure then that changes everything. You would not want alot of roostrs in a building with so many hens. You would have alot of fights. If you are not planning on breeding then do not worry about the roosters.