How Big a Coop Do 27 Chickens Need?

27 standard-size chickens need a 108 sq ft coop, a 270 sq ft run, 270 inches of roost, and 7 nesting boxes.

Bird typeCoopRunRoostNest boxes
Standard breeds108 sq ft270 sq ft270 in7
Bantams54 sq ft216 sq ft216 in7
Heavy breeds135 sq ft270 sq ft324 in7

Rates: 4 sq ft coop and 10 sq ft run per standard bird (Virginia Cooperative Extension; Colorado State University Extension). Run figures assume birds are confined; free-range flocks need only the coop numbers.

What that looks like in practice

For 27 standard chickens, a 6 × 18 ft coop covers the108 sq ft floor requirement. Floor space means usable floor — don't count feeder footprints or the area under nest boxes mounted lower than 18 inches. The 270 sq ft run works out to roughly a27 × 10 ft enclosure attached to the coop.

Inside, plan 270 inches of roost — 6 four-foot roost bars mounted higher than the nest boxes — and 7 twelve-inch nesting boxes in the darkest corner. These are extension-guidance minimums for healthy birds, not luxury targets: cold climates, bossy roosters, and pecking-prone breeds all appreciate more room.

Keeping different birds, or planning to free-range? Use the full Coop Size Calculator to adjust for bantams, heavy breeds, and run type.

Other flock sizes