Calculate minimum indoor coop square footage, outdoor predator-proof run area, roosting perch length, nesting box count, and passive ventilation requirements.
Always plan for 2 to 4 additional birds ("chicken math") to avoid rapid overcrowding.
Prevent cannibalistic feather pecking, fatal ammonia buildup, and cracked dirty eggs.
Overcrowding triggers severe behavioral stress in chickens, escalating from aggressive pecking order battles to bloody flock cannibalism. Our scientific floor calculations guarantee birds sufficient personal flight and loafing distance.
Chicken manure emits pungent ammonia fumes, and nighttime breathing generates heavy moisture. Without adequate high-ridge passive ventilation (10% floor ratio), trapped moisture freezes on combs causing severe winter frostbite.
Having too few nesting boxes forces hens to stack on top of one another, trampling and cracking freshly laid eggs. This tool delivers the optimal 1 box per 3-to-4 hen ratio to maintain clean, unbroken clutches.
Chickens possess a deep instinct to sleep high off the ground away from raccoons and rodents. Providing 10-12 inches of horizontal perch space per bird prevents frantic nighttime jockeying and falls.
Five intuitive steps to plan an ergonomic, healthy coop and run blueprint.
Input your target number of laying hens, plus 2-3 extra birds to accommodate inevitable flock growth.
Pick Bantam (2 sq ft), Standard (4 sq ft), or Giant/Heavy breeds (5 sq ft) for correct space scaling.
Indicate whether your flock has daily run access, is strictly confined (+25% space), or free ranges full-time.
Examine required linear roosting length, 12x12" nesting box counts, and ridge soffit ventilation screen area.
Click Copy Coop Sizing Specs to save dimensions for your lumber takeoff and build plans.
Engineered based on university agricultural extension poultry welfare guidelines.
Differentiates between delicate bantam varieties and heavy 10-lb heritage breeds (like Jersey Giants and Brahmas) that require wider roost perches and deeper floor clearance.
Calculates required square footage of permanent predator-proof 1/2" hardware cloth soffit vents positioned above roost level to extract ammonia without drafting birds.
Provides a live visual blueprint showing coop-to-run orientation, roosting bar offset margins, private nesting box bays, and predator-resistant pop door connections.
Accounts for northern winter climates where heavy blizzards trap chickens indoors for consecutive weeks, adjusting coop square footage to prevent cold-season cabin fever.
Recommended minimum space per bird across poultry categories (Extension Services).
| Breed Classification | Indoor Coop Space | Outdoor Run Space | Roost Length / Bird | Nesting Box Size | Feeder Space / Bird |
|---|---|---|---|---|---|
| Bantam (Miniature) | 2.0 sq ft (0.19 m²) | 5.0 sq ft (0.46 m²) | 8 inches (20 cm) | 10" x 10" x 10" | 2.0 inches |
| Standard / Medium | 4.0 sq ft (0.37 m²) | 10.0 sq ft (0.93 m²) | 10 - 12 inches (25-30 cm) | 12" x 12" x 12" | 3.0 inches |
| Heavy / Giant Breeds | 5.0 sq ft (0.46 m²) | 12.0 - 15.0 sq ft | 12 - 15 inches (30-38 cm) | 14" x 14" x 14" | 4.0 inches |
| Confined (No Run Access) | 10.0 sq ft (0.93 m²) | N/A (Coop Only) | 12 - 14 inches | 12" x 12" x 12" | 3.5 inches |
| Pasture Free Range | 2.5 sq ft (Night Only) | Unlimited / Pasture | 10 inches | 12" x 12" x 12" | 3.0 inches |
Practical coop building, predator protection, and flock management questions.
