I had 17 chickens, but I lost 3 somehow, but one of those came back after 2 days so now I have 15 chickens in total.
I feed them 50 grams of bought food per day per chicken, so about 700 grams of bought food per day for 15 chickens.
Google recommends 100 to 150 grams per chicken, but I only feed 50 grams because it pays off more.
About 3 hours before sun set, I let chickens out of fence so they can forage for grass and insects for about hour or two.
That way, food expenses are greatly reduced.
Food for chickens right now per day costs about as much as price of two eggs, but they lay 6 to 12 eggs almost every day. I had only one day where they layed only 3 eggs. Their average is about 8 or 9 eggs per day.
So you could say I get about 4 times more food out of chickens than I give to chickens.
I give them some mowed grass too, but thats free.
Its hard work to watch them while they forage, since I need to make sure they dont leave my land or that they dont get attacked by birds or dogs.
The hardest work is probably cleaning the coop. For some reason, they poop a lot inside the coop instead of outside, which is annoying.