Free tool
Chicken Coop Size Calculator
Tell it your flock and it hands back the coop floor, run size, nesting boxes and roost length you need — each from a published rule, with the math shown so you can check it.
Coop floor
24 sq ft
about 4 x 6 ft
Run (outdoor)
60 sq ft
about 8 x 8 ft
Rules used: 4 sq ft of coop floor and 10 sq ft of run per bird, 1 nesting box per 3-4 hens, and 10 inches of roost per bird. These are comfortable home-flock minimums, not hard limits. More room is always better, and crowding is the single most common cause of pecking and mess.
How much space a chicken needs
The number most keepers work from is 4 square feet of coop floor per standard-size hen, plus a run of 8 to 10 square feet per bird. It is a minimum, not a target. The coop is only where they sleep and lay, so the floor figure is modest; the run is where they spend the day, so that is where extra room pays off. Bantams get by on about 2 square feet of coop, and heavy breeds like Orpingtons and Brahmas want closer to 5.
Coop floor vs. run
Keep the two numbers separate. A coop that is generous on paper can still give a flock nowhere to be all day if the run is an afterthought, and that is where the trouble starts: crowded birds pick feathers, foul their water and turn a run to mud. If your birds are shut in the coop most of the day, tick the box in the calculator — a confined flock needs the coop itself to carry 8 to 10 square feet per bird, because it is doing the run's job too.
Why prefab coop capacity claims run high
A coop sold "for 8 chickens" is very often a 4-bird coop with a run bolted on, because the headline count quietly includes the run as living space. Before you buy, measure the enclosed sleeping area and divide by 4 square feet. That is the honest capacity, and it is usually about half the box number. Our full guide to flock space works through the exceptions.
Chicken coop size chart
If you would rather read it off a chart than run the calculator, here is the same math for common flock sizes, at 4 square feet of coop floor and 10 of run per standard hen, one nest box per four hens, and 8 inches of roost bar each.
| Flock | Coop floor | Run | Nest boxes | Roost bar |
|---|---|---|---|---|
| 2 hens | 8 sq ft | 20 sq ft | 1 | 16 in |
| 4 hens | 16 sq ft | 40 sq ft | 1 | 32 in |
| 6 hens | 24 sq ft | 60 sq ft | 2 | 48 in |
| 8 hens | 32 sq ft | 80 sq ft | 2 | 64 in |
| 10 hens | 40 sq ft | 100 sq ft | 3 | 80 in |
| 12 hens | 48 sq ft | 120 sq ft | 3 | 96 in |
| 15 hens | 60 sq ft | 150 sq ft | 4 | 120 in |
These are minimums. Bantams get by on about half the coop floor; heavy breeds like Orpingtons and Brahmas want a little more. A flock kept shut in most of the day needs the coop itself to carry the run number, 8 to 10 square feet per bird.
What about ducks?
Ducks need more room than chickens and make far more mess, so size up rather than down. Give each duck about 4 to 6 square feet of shelter floor and at least 15 square feet of run, plus daily access to water deep enough to dunk their heads. The coop and run figures from the calculator are a fair starting point for a duck flock if you take the higher end, but ducks do not roost and they nest on the ground, so ignore the roost-bar and nest-box numbers, and give them a low, dry nesting corner with clean bedding instead.
Gear that fits the numbers
Once you know the coop floor and run area, this is the gear that builds it — the coop, the mesh that keeps the run predator-proof, and the door that shuts the flock in at dusk.
Aivituvin
Aivituvin Large Wooden Chicken Coop & Run
A solid mid-size wooden coop-and-run for a small standard flock. Measure the enclosed sleeping space against the coop-floor number above before you buy — prefab capacity claims usually count the run.
Amagabeli
Amagabeli 1/2 in 19-Gauge Hardware Cloth (48 in x 100 ft)
The run number is only safe if a raccoon cannot reach through it. Half-inch 19-gauge hardware cloth is the mesh that keeps a run predator-proof — chicken wire does not.
Premier 1
Premier 1 PoultryNet Plus Starter Kit
If your run area is bigger than a fixed pen, electric poultry netting fences the daytime range you calculated and moves when the grass wears out. Strong daytime deterrent, not an overnight wall.
ChickenGuard
ChickenGuard Automatic Coop Door Opener
Once the coop and run are sized, the door is what shuts the flock in at dusk without you there. ChickenGuard is the timer-and-light opener keepers report the longest service from.
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