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Chicken coop size calculator

How many hens, what size of bird, and do they get a run? The chicken coop size calculator gives the floor, nest boxes, roost and vents they need, and the smallest of our coop plans that passes every check.

Changes update the result straight away.

SpaceOur defaultLeast a source accepts

How the coop size is worked out

Floor space per bird depends on whether the hens get a run. With a run they spend the day outside and the coop is for sleeping and laying; shut in, the coop is their whole world. Our default sits inside the range the extension services give, and the least accepted figure is the smallest one any of them gives.

BirdCoop, with a runCoop, shut inRunRoost
Bantam2 sq ft (least 1)5 sq ft (least 4)6 sq ft (least 4)6 in (least 4)
Standard laying hen4 sq ft (least 3)10 sq ft (least 8)10 sq ft (least 4)8 in (least 6)
Large or heavy breed5 sq ft (least 3.5)12 sq ft (least 10)12 sq ft (least 10)10 in (least 8)

Once you know the size, the free coop plans give the materials list for each one, and the chicken run size calculator sizes the run. The coop designer takes the same flock and draws the whole coop.

Questions people ask

Only just. A 4x8 coop has 25.3 sq ft inside its walls, which gives eight standard hens 3.2 sq ft each: above the 3 sq ft the sources accept, below our 4 sq ft default, so the check is amber. Six hens fit it with room to spare.

A 10x10 coop has 88.7 sq ft inside, enough for 22 standard hens that also have a run, or 44 bantams. Kept inside all day, it holds 8 standard hens at 10 sq ft each.

Twelve standard hens with a run need 48 sq ft of coop floor and at least 36. The smallest of our sizes that passes every check is 8x8, with 55 sq ft inside, 3 nest boxes and a run of 120 sq ft.

Yes. A 4x8 coop measured over the siding is 32 sq ft, but the hens live on the floor inside the walls, which is about 25 sq ft once 2x4 framing and siding take their share. The calculator and the designer both use the inside figure.