How big of a coop do you need? Enter your flock size and bird type to get coop floor area, run size, nesting boxes, roost length, feeder/waterer sizes, and suggested coop dimensions — with both minimum and comfortable standards shown side by side.
Standard breeds (Rhode Island Red, Plymouth Rock, Leghorn): 2–4 sq ft indoor, 8–10 sq ft run per bird.
The widely cited minimums are 2–4 sq ft of coop space per bird and 8–10 sq ft of run per bird. Use the high end (4 sq ft indoors, 10 sq ft of run) if the birds are confined most of the day; the low end only works if they free-range. Bantams need roughly half as much, and large breeds like Brahmas, Cochins, and Orpingtons do best at or above the top of the range.
Yes, but only with trade-offs. A coop at the 2 sq ft/bird minimum works when the flock spends its days in a large run or free-ranges — the coop is then mainly for sleeping and laying. Birds confined in a small coop around the clock get bored, pick feathers, and suffer ammonia buildup from droppings, which invites respiratory disease. If confinement is the norm, build to 4 sq ft per bird indoors and 10 sq ft per bird in the run, and add perches, dust-bath areas, and enrichment.
Bantams are quarter- to half-size chickens, so about 1–2 sq ft per bird indoors and 4–5 sq ft per bird in the run is adequate. Nesting box math is unchanged (1 box per 3–4 hens) and 8 in of roost per bird still applies, though bantams can perch slightly closer together. Note that bantams fly better than large fowl, so taller fencing or a covered run matters more.
Strongly recommended, even if you free-range. A predator-proof run gives birds daily daylight, exercise, dust bathing, and foraging while keeping them safe when you are away or the weather is bad, and it protects garden beds from scratching. Plan 8–10 sq ft of run per standard bird; if the flock never free-ranges, go with the full 10 sq ft and consider a covered top against aerial predators.