Your Flock
Results
Chicken Coop Size Calculator Guide
Overcrowding is the single most common mistake in backyard chicken keeping, and it causes feather-picking, disease, and stopped laying. This chicken coop size calculator sizes the coop, run, nesting boxes, and roosting bar for your flock.
Standard chickens need about 4 sq ft each inside the coop and 10 sq ft each in the run. Add one nesting box per 3–4 hens and 8–12 inches of roosting bar per bird.
How Much Coop Space per Chicken?
Four square feet per standard bird is the widely used minimum for a coop with an attached run. Six hens therefore need about 24 sq ft of coop — roughly a 4 × 6 ft floor — plus a 60 sq ft run. Bantams manage with about 2 sq ft each; large breeds want 5 or more.
Nesting Boxes and Roosts
You need far fewer nesting boxes than you'd think — one per 3 to 4 hens is plenty, because hens queue for the same favourite box no matter how many you provide. Roosting bars matter more: chickens sleep on them, and each bird needs 8 to 12 inches of bar. Roosts should sit higher than the nesting boxes, or the hens will sleep in the boxes and foul the eggs.
Free Range Changes the Maths
Birds that free range all day need only the coop for sleeping and laying, so you can skip the run entirely. Part-time ranging halves the run requirement. If your flock is fully confined, err generous — cramped birds start pecking each other, and that's very hard to stop once it begins.
This is a general estimate for information only, not veterinary advice. Every animal is different — always consult your veterinarian for guidance on your pet's health, diet, and care.
Related: Goat Gestation Calculator, Sheep Gestation Calculator, and Cow Gestation Calculator.
Frequently Asked Questions
How much coop space does a chicken need?
About 4 square feet per standard bird inside the coop, plus 10 square feet each in an attached run. Bantams need roughly 2 square feet.
How many nesting boxes do I need?
One box per 3 to 4 hens is plenty, since hens tend to share and queue for the same favourite box regardless of how many you build.
How much roosting bar per chicken?
Allow 8 to 12 inches of bar per bird, and set the roost higher than the nesting boxes so hens don't sleep in the boxes.
What happens if a coop is too small?
Overcrowding causes feather-picking, bullying, disease spread, and hens stopping laying, so always err on the generous side.
Need a Calculator We Don't Have Yet?
Can't find the calculator you need? We'll build it. Submit your request and we'll evaluate it for our growing collection.
Request Calculator