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Chicken Coop Size Calculator

Use this chicken coop size calculator to find out how much chicken coop space to provide your chickens to make them happy.

Clear
Coop area needed24 sq ft6 × 4 sq ft each
Suggested coop size5 × 5 ftroughly square, rounded up to whole feet
Run area needed60 sq ft10 sq ft each
Total area84 sq ft
Run fencing31 ftperimeter of a square run of that area
Nest boxes2one per 4 birds
Roost length48 in4 ft at 8 in per bird
AnimalStandard chickencoop plus run
Ventilation opening2.4 sq ftabout a tenth of the floor area, high up and draught-free
Crowding warningmore space is always betterthese are minimums — crowded birds feather-pick, fight and spread disease

The formula

area = animals × space each, inside and out

Minimums, not targets

Four square feet of coop and ten of run per standard hen is the usual guidance, and it is a floor rather than a goal. Crowding is the root cause of feather-picking, bullying and most disease problems in a small flock — and the cost of extra space is trivial next to the cost of dealing with those.

Confined birds need roughly double the indoor space, because the coop is their whole world. Birds that genuinely free-range need less, since the coop is only for roosting and laying.

Ventilation matters as much as area. Aim for about a tenth of the floor area in openings, placed high so the air moves without blowing directly on the roosts — moisture, not cold, is what harms poultry in winter.