ChickenCoopCalc

How big should a chicken coop be for 6 hens?

24 sq ft inside, 60 sq ft of run, 5 feet of roost bar, 2 nesting boxes — one formula, four numbers, no marketing nonsense.

The formula from the extension services

Coop: 4 sq ft per standard bird. Run: 10 sq ft per bird. Six hens → 24 sq ft of coop floor and 60 sq ft of run. Bantams get half indoors (2 sq ft/bird); large breeds like Brahmas deserve a floor up (5 sq ft/bird).

These aren't hobby-forum numbers — 4/10 is the standard published by state extension services, and it's driven by behavior: chickens crowded below it start feather-pecking, egg-eating, and bullying the bottom of the pecking order. The minimum is a floor, not a target.

The six-hen spec, line by line

Spec6 hensWhy
Coop floor24 sq ft4 sq ft/bird; e.g. 4×6 ft
Run60 sq ft10 sq ft/bird; e.g. 6×10 ft
Roost bar4–5 ft8–10 in/bird, flat 2×4, not round
Nesting boxes21 per 3–4 hens, 12×12×12 in
Ventilation2.4+ sq ft, high1 sq ft vent per 10 sq ft floor; see the winter guide
Pop door10×12 inOne up, one down comfortably

The full flock-size chart

FlockCoopRunRoostBoxes
3 hens12 sq ft30 sq ft2.5 ft1
6 hens24 sq ft60 sq ft5 ft2
8 hens32 sq ft80 sq ft7 ft2–3
12 hens48 sq ft120 sq ft10 ft3–4
20 hens80 sq ft200 sq ft17 ft5–6

The prefab-label trap

Coops marketed as "fits 6–8 chickens" routinely measure 12–16 sq ft inside — half the standard. Manufacturers size labels to buyer optimism, not bird behavior. The fix is mechanical: read the interior dimensions, divide by 4, and that's the true bird count. Our best coops for 6 hens guide applies exactly that test to the 2026 prefab market — anything genuinely 24+ sq ft for six birds runs $600–1,200, and sub-$400 "cute" coops essentially never qualify.

Run size when chickens free-range

True free-ranging (out most of the day, supervised) lets you shrink the run toward 5–8 sq ft/bird — but never the coop. Birds are locked in every night and every winter evening, and 4 sq ft inside holds regardless of how much lawn they own by day. A 60 sq ft predator-proofed run plus supervised yard time is the comfortable six-hen setup; "free-range" with no run at all usually ends in a raccoon census.

Sizing up on purpose

Three reasons real builders land above the minimum:

A 4×8 ft shed-style coop (32 sq ft) with a 6×12 run is the sweet-spot six-hen build: above minimum, standard lumber sizes, one sheet-goods-friendly footprint.

Affiliate

The spec list maps directly to hardware: 1/2-inch hardware cloth, predator-proof two-step latches, flat roost bars, and 12×12 nesting boxes.

After the coop: the monthly math

Size is the one-time decision; feed is the forever one. Six hens eat roughly 46 lb of layer feed a month — about one 50 lb bag — and the feed cost guide breaks that down per flock size, per egg, and per brand. The coop calculator handles any flock size in one step.

FAQ

How big should a coop be for 6 hens?

24 sq ft inside (4 sq ft/bird) plus a 60 sq ft run (10 sq ft/bird), with about 5 ft of roost bar and 2 nesting boxes. That's roughly a 4×6 coop on a 6×10 run — and building 32 sq ft instead covers the flock growth that's coming anyway.

Can 6 chickens live in a small prefab coop?

Almost none sold as "6–8 bird" coops actually offer 24 sq ft inside — most are 12–16. Divide the listed interior dimensions by 4 to get the true capacity. Real six-hen prefabs run $600–1,200.

Do bantams need less space?

Yes — 2 sq ft/bird indoors and 8 sq ft/bird in the run is the accepted bantam standard. Six bantams fit a 12 sq ft coop; the nesting and roost specs barely change.

Sizing tools for the rest of the homestead: GeneratorSizer ↗, SolarSizer ↗, Battery Bank Sizer ↗.