Flocks of 1–50 birds · 28 breed profiles · updated July 2026
Chicken coop size calculator
Set the flock size and the numbers follow the space guidance most keepers work from: four square feet a bird inside the coop, ten in the run, one nest box per four hens. Treat them as floors, not targets — crowded birds pick at each other.
chickens
4 sq ft per bird in the coop, 10 sq ft in the run, one nest box per four hens, and 250 eggs per hen per year. Breed and age move the egg number a lot.
How big should a chicken coop be?
The working rule is 4 square feet per chicken inside the coop and 10 square feet per chicken in the outdoor run. Heavy breeds like Brahmas and Jersey Giants want more; bantams get by with less. Birds that stay shut in all winter need the upper end of the range, because boredom in a tight coop turns into feather picking fast.
Nest boxes are the opposite problem — hens share them and will queue for a favorite even when others sit empty, so one box per four hens is plenty. Roost space matters more: budget about 8 inches of bar per standard bird.
The egg figure assumes 250 eggs per hen per year, which is roughly what a healthy production hen manages in her first two years. Real output swings with breed, daylight, molt, and age — an ornamental breed may lay 70 a year while a hybrid layer pushes 320. The breed guide lists the numbers per breed, and how this site works covers where they come from.