How this calculator works
Poultry guides give the minimum space per bird: about 3 to 4 square feet inside the coop for standard breeds (2 for bantams, 5 for large breeds), and 8 to 10 square feet per bird in the outdoor run. Nesting boxes are shared at roughly one per four hens, and each bird needs 8 to 12 inches of roost bar.
Worked example: six standard hens need a 24 ft² coop (a 4 × 6 ft house), a 60 ft² run (such as 6 × 10 ft), two nesting boxes, a 5 ft roost bar, and about 6 ft² of ventilation.
Tips before you buy
- Build for more birds than you start with. Most people end up wanting more chickens, and a coop is much easier to size up front than to add on.
- Ventilation matters more than warmth. Chickens tolerate cold well, but ammonia and damp cause respiratory trouble, so keep high vents open year-round (and draft-free at roost height).
- Check local rules: many places restrict flock size, roosters, and how close a coop can be to a property line.
- Raise the coop off the ground, put a roof over the nesting boxes, and build in an easy way to clean the floor.
Tools & materials for this project
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Frequently asked questions
How many square feet per chicken in a coop?
About 3 to 4 square feet inside the coop for standard-size hens, plus 8 to 10 square feet per bird in an outdoor run. Bantams need less, and large breeds more.
How many nesting boxes do I need?
One box for every 4 or 5 hens is enough. Hens often share their favourite, and having more boxes than needed does not help.
How big should a coop be for 6 chickens?
At least 24 square feet inside (such as 4 × 6 ft) and at least 60 square feet of run, though more is better.
Related calculators & guides
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.