Chicken Coop Calculator
Size a chicken coop, run, roost and nest boxes from flock size and published extension space standards.
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What this tool does
Size a chicken coop, run, roost and nest boxes from flock size and published extension space standards. Defaults follow common university-extension guidance for standard laying hens: ~4 sq ft per bird inside, ~10 sq ft in the run, 8–10 in of roost per bird and one nest box per 4 hens. Bantams need less, heavy breeds and confined (no free-range) flocks need more.
How to use the Chicken Coop Calculator
- Enter or select number of chickens.
- Enter or select coop space per bird (sq ft).
- Enter or select run space per bird (sq ft).
- Enter or select roost space per bird (in).
- Read the calculated result; change any measurement to compare alternatives.
Formula
coop area = birds × sq ft per bird; run area = birds × run sq ft per bird; roost length = birds × inches per bird / 12; nest boxes = ceil(birds / 4)
- birds
- Number of chickens
- coopPer
- Coop space per bird (sq ft)
- runPer
- Run space per bird (sq ft)
- roostPer
- Roost space per bird (in)
Defaults follow common university-extension guidance for standard laying hens: ~4 sq ft per bird inside, ~10 sq ft in the run, 8–10 in of roost per bird and one nest box per 4 hens. Bantams need less, heavy breeds and confined (no free-range) flocks need more.
Worked example
For chicken coop calculator, the following measurements illustrate the exact method: Number of chickens: 12; Coop space per bird (sq ft): 4; Run space per bird (sq ft): 10; Roost space per bird (in): 10.
Inputs
- Number of chickens12
- Coop space per bird (sq ft)4
- Run space per bird (sq ft)10
- Roost space per bird (in)10
Result
- Minimum coop area48 sq ft
- Minimum run area120 sq ft
- Roost length10 ft
- Nest boxes3
Results explained
- Minimum coop area
- Minimum coop area from the formula above, expressed in sqft before metric conversion. Defaults follow common university-extension guidance for standard laying hens: ~4 sq ft per bird inside, ~10 sq ft in the run, 8–10 in of roost per bird and one nest box per 4 hens. Bantams need less, heavy breeds and confined (no free-range) flocks need more.
- Minimum run area
- Minimum run area from the formula above, expressed in sqft before metric conversion. Defaults follow common university-extension guidance for standard laying hens: ~4 sq ft per bird inside, ~10 sq ft in the run, 8–10 in of roost per bird and one nest box per 4 hens. Bantams need less, heavy breeds and confined (no free-range) flocks need more.
- Roost length
- Roost length from the formula above, expressed in ft before metric conversion. Defaults follow common university-extension guidance for standard laying hens: ~4 sq ft per bird inside, ~10 sq ft in the run, 8–10 in of roost per bird and one nest box per 4 hens. Bantams need less, heavy breeds and confined (no free-range) flocks need more.
- Nest boxes
- Nest boxes from the formula above. Defaults follow common university-extension guidance for standard laying hens: ~4 sq ft per bird inside, ~10 sq ft in the run, 8–10 in of roost per bird and one nest box per 4 hens. Bantams need less, heavy breeds and confined (no free-range) flocks need more.
Frequently asked questions
At the extension standard of 4 sq ft per bird inside, 12 hens need 48 sq ft of coop (e.g. 6 × 8 ft) and about 120 sq ft of run.
About 10 sq ft per bird is the common extension minimum for an enclosed run. Free-ranging part of the day relieves run pressure but does not shrink the coop requirement.
One box per 4 hens, so 3 boxes — hens share happily and more boxes mostly sit empty (or collect eggs in one favourite anyway).
8–10 inches per bird on the roost bar; in hot climates give 10–12 so birds can spread out and cool off.
Fully confined birds need more indoor space — many keepers use 8–10 sq ft per bird inside for welfare and litter management. Increase the per-bird inputs to match your setup.