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Multiply hens by 4 square feet for indoor coop floor area, and by 10 square feet for outdoor run area. Six hens need 24 square feet inside and 60 square feet outside, before sizing up for large breeds, winter confinement, or a growing flock.
Hens need about 4 square feet each inside the coop and about 10 square feet each in the run. Crowding raises stress, pecking, and disease, so these figures are planning minimums, not a target to squeeze under. A 10 by 10 foot coop gives 100 square feet, which is 25 hens of indoor space by the 4 square foot rule, but feeders, waterers, and roosts take floor space too, so plan usable floor, not just the shell size.
Use this table for standard hens with a run: 4 hens need 16 square feet of coop and 40 square feet of run, 6 hens need 24 and 60, 10 hens need 40 and 100, 12 hens need 48 and 120, and 20 hens need 80 and 200. A 6 by 8 foot coop gives 48 square feet, which is comfortable floor space for about 12 standard hens before equipment is counted. If you plan to add birds later, build for the flock you expect to have, because coop expansion is usually harder after the run and fencing are in place.
Bantam chickens need about half the space of a standard bird, roughly 2 square feet inside and 4 to 6 square feet in the run, with about 4 inches of roost each. Standard hens need 4 square feet inside and 10 square feet in the run, with 8 to 12 inches of roost each. Heavy breeds such as Jersey Giants and Brahmas need 6 to 8 square feet inside and 10 to 15 square feet in the run, plus wider doors and more landing room around ramps. Size a mixed flock for the larger birds.
Hens share nesting boxes, so one box per 3 to 4 hens is plenty, with each box about 12 by 12 inches. Place nesting boxes lower than the roosts, so birds do not sleep in them and soil the bedding. Allow 8 to 12 inches of roost length per hen, on a flat 2 by 4 laid flat, 2 to 4 feet off the ground, with more than one roost level for flocks over 4 hens, because dominant birds claim the highest spots. Do not count raised nesting boxes as open floor area.
If hens free range most days, the coop can stay near the minimum, but ventilation, predator protection, and roost layout still matter. If hens are confined to the run full time, go bigger, toward 15 square feet of run per bird. In winter, hens spend more time inside, so size up for cold climates and add ventilation above roost height: vents remove moisture, odour, and ammonia, but avoid drafts directly on sleeping birds. A snug, dry, well ventilated coop stays warmer than a large draughty one.
Enter the number of hens, then read the coop floor area and run area together. For a backyard flock, deciding how big to build is the main choice: check the result against the table, then add roost length and nesting boxes from the sections above. If the flock may grow, if breeds are large, or if winter confinement is likely, build bigger than the minimum. More space is always better for health and laying, while a coop that is too small costs more in stress and vet trouble than it saves in timber.
About 4 square feet per hen inside the coop, plus about 10 square feet per hen in the outdoor run. Bantams need about half, and large breeds need more.
Yes, but less. Free range hens still need a secure run for days when they cannot roam, and the run is where they forage, dust bathe, and stretch. Keep the run generous even for free range flocks.
One nesting box per 3 to 4 hens is plenty, because hens share and often queue for a favourite box. Each box should be about 12 by 12 inches, placed lower than the roosts.
Allow 8 to 12 inches of roost length per hen, on a flat surface 2 to 4 feet off the ground. Give more than one roost level for larger flocks, so timid hens are not forced off the perch.
A 10 by 10 coop gives 100 square feet, which is 25 hens by the 4 square foot indoor rule. In practice, feeders, waterers, and roosts reduce usable floor, so plan for fewer birds or a larger coop if equipment is bulky.
Yes, especially in cold climates where hens spend more time indoors. Add ventilation above roost height to remove moisture and ammonia, without drafts directly on sleeping birds.
No. Coop size is indoor shelter space for sleeping, laying, and lockup. Run size is the outdoor fenced area for daytime movement, scratching, and dust bathing.