Chicken Coop Size Calculator — Space Per Hen
Enter the number of chickens and breed size to get the recommended minimum coop floor area, run size, number of nest boxes, and roost bar length based on standard poultry-keeping guidelines.
Breed size
Outdoor run
Interior floor space for the coop structure
- 1
Indoor space per bird
2 sq ftMinimum floor space from standard poultry-keeping guidelines for this breed size. - 2
Minimum indoor floor area
6 birds × 2 sq ft/bird = 12
How does this calculator work?
Coop floor = n × 2 sq ft (standard hens), run = n × 8 sq ft, nest boxes = ⌈n/4⌉, roost bar = n × 10 in. For 6 standard hens: 12 sq ft coop, 48 sq ft run, 2 nest boxes, 5 ft roost. These are minimums; doubling them improves welfare and laying. Heavy breeds need more space; bantams need less.
Formula
How this is calculated
The most widely cited poultry-keeping guidelines (Storey's Guide to Raising Chickens, RSPCA Five Freedoms, USDA organic standards) recommend 2 sq ft per standard-size hen indoors as an absolute minimum, 4 sq ft for heavy breeds and 1 sq ft for bantams. Cramped conditions cause feather-pecking, increased disease spread and a measurable drop in egg production. The outdoor run recommendation is 8 sq ft per standard hen; heavy breeds need more room (10 sq ft) while bantams need slightly less (6 sq ft). Both indoor and run figures are hard minimums — experienced keepers commonly double these for healthy, happy birds.
Nest boxes are sized at one box per 3–4 hens: hens will share boxes but competition causes broken eggs and egg-eating. Roost bars should provide 8–12 inches per bird (this calculator uses 10 in as a middle estimate); bars more than 18 inches high should have a ramp for heavier breeds. The calculator suggests a practical rectangular footprint with a width-to-depth ratio of roughly 1.5:1 to allow adequate ventilation and easy access.
All values are minimums based on published guidelines for small-flock backyard keepers. Local ordinances, climate, breed temperament and flock management style (deep litter, slatted floors, etc.) may change optimal sizing. When in doubt, go larger.
Frequently asked questions
For 6 standard-size hens, the minimum indoor floor area is 12 sq ft (2 sq ft per bird). An outdoor run should be at least 48 sq ft (8 sq ft per bird). You will need 2 nest boxes and about 5 feet of roost bar. These are absolute minimums; 24 sq ft of indoor space and 80 sq ft of run are comfortable targets.
Ten hens need 3 nest boxes (one per 3–4 hens). Hens tend to share favourite boxes and will queue rather than use an "unpopular" one, so having enough popular positions prevents egg breakage and egg-eating behaviour. Boxes should be dark, slightly raised, and lined with fresh bedding.
Yes — many keepers use a fully free-range setup in a fenced yard. In that case there is no fixed run to size, but you should still ensure the birds have adequate space to forage (at least 8–10 sq ft per bird is a reasonable lower bound even for free-range). The coop itself should still meet the indoor minimum, as birds spend nights and bad-weather days inside.
TG we-Calculate Editorial Team. (2026). Chicken Coop Size Calculator — Space Per Hen [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/chicken-coop-size-calculator
TG we-Calculate Editorial Team. "Chicken Coop Size Calculator — Space Per Hen." TG we-Calculate. 2026. https://we-calculate.com/calculator/chicken-coop-size-calculator.
TG we-Calculate Editorial Team, "Chicken Coop Size Calculator — Space Per Hen," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/chicken-coop-size-calculator
@misc{wecalculate_chicken_coop_size_calculator, title = {Chicken Coop Size Calculator — Space Per Hen}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/chicken-coop-size-calculator}}, year = {2026}, note = {TG we-Calculate} }
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