Chicken Coop Size Calculator

Coop Space Requirements Overcrowding is the #1 cause of disease, pecking, and stress in backyard flocks. Minimum coop floor space: Standard breeds (Rhode Island Red, Orpington, Plymouth Rock): 4 sq ft (0.37 m²) per bird inside Large/heavy breeds (Jersey Giant, Brahma): 5–6 sq ft per bird Bantam breeds (Silkie, Sebright): 2 sq ft per bird Cold climates where birds spend long periods inside: add 25–50%

Run / Outdoor Space Attached outdoor run: Standard breeds: 10 sq ft (0.93 m²) per bird minimum; 15–20 sq ft ideal Free range / large paddock: 250+ sq ft per bird Confined run with no free range: at least 15 sq ft per bird to prevent boredom

Roost Bars Chickens sleep perched on roost bars, not on the floor. Space per bird: 8–12 inches (20–30 cm) of roost length per bird Position: at least 18" from walls and 12" apart if multiple levels Height: 18–24" above floor minimum; not too high to prevent leg injuries on dismount

Nesting Boxes 1 nesting box per 4–5 hens (hens share boxes, they take turns). Size: 12" × 12" (30 × 30 cm) for standard breeds; 14" × 14" for large breeds. Position: lower than roost bars (so hens don’t sleep in them). Provide fake eggs (golf balls) to encourage use.

Ventilation Minimum: 1 sq ft of ventilation per 10 sq ft of floor space. Ammonia from droppings damages lungs — ventilation is critical even in winter. Vents near the top of the coop; draft-free at roost level. Deep litter method: 4–6" of bedding (pine shavings, straw) absorbs droppings.