Chicken run size calculator
The run is where your flock spends its waking life, and it is where almost every predator loss happens. This works out the area you need, a shape you can actually build, and how much fencing, mesh and apron to buy — in feet or in metres.
At this size, expect bare earth. Grass will not survive this density in a static run.
How this compares to the recognised standards
Space allowances are not identical from one country to another, and no calculator we could find tells you that. Here is what the main welfare bodies recommend for your flock of 6, alongside our own figure — including where ours is the more cautious and where it is not.
| Source | Coop / housing | Run or total |
|---|---|---|
| FlockSavvy (this page) | 24 sq ft | 60 sq ft of run |
| US extension services | 18–24 sq ft | 48–60 sq ft of run |
| RSPCA (UK) | 6 m² ideally, 2 m² floor | no numeric figure published for the run |
| British Hen Welfare Trust (UK) | run figure only | 6–12 m² of run |
| RSPCA (Australia) | given as a combined figure → | 4.2 m² of coop and run together |
Read this honestly. Our 4 sq ft per standard hen of coop floor sits at the generous end of the US extension range, but it is well below what the RSPCA in the UK recommends — they ask for 1 m² (about 10.8 sq ft) per bird of housing where possible, and set 3 birds per m² as the point you should never pass. If you are in the UK, treat our figure as the floor and theirs as the target. We would rather say that than pretend one number fits every country.
Notice which column is empty. The RSPCA gives the most demanding housing figure we found and no figure at all for the run; the British Hen Welfare Trust does the reverse. Between them, a UK keeper has a coop standard and a run standard — but they have to read two organisations to get both, which is why they are side by side here.
Sources, checked 2 September 2026: RSPCA (UK), keeping chickens as pets — 1 m² per bird where possible, never more than 3 birds per m² of coop; one nest box per five hens, minimum two, 30 × 30 × 30 cm. British Hen Welfare Trust, getting set up to adopt hens — a run allowing 1 m² of clear floor space per ex-caged hen, or 2 m² per hen from other farming systems, plus daily ranging; and the rule of buying to the smallest flock size a coop is sold for. RSPCA Australia knowledgebase — minimum 3 m² of combined floor and run for three large birds or six bantams, plus 0.4 m² for each extra large bird and 0.3 m² for each extra small one; described as recommendations, not law. poultry.extension.org — US extension space allowances. For mixed flocks the Australian base allowance counts a bantam as half a large bird; that reading is ours, not theirs.
What does the law where you live require? Usually far less than any of these, and sometimes nothing at all. We read the ordinances and put them side by side: how much space is a backyard hen entitled to?
Where the figures come from
| Run area | 10 sq ft (0.93 m²) per standard bird, 6 sq ft (0.56 m²) per bantam — increased by half if the run is their only outdoor space, reduced by a third if they free-range most of the day |
|---|---|
| Shape | Long and narrow beats square at the same area: birds use the length, and a 6 ft width lets you reach the middle from either side |
| Mesh | Perimeter × height, plus 10% for overlap at seams. ½ in hardware cloth to 3 ft minimum |
| Apron | 18 in (45 cm) of hardware cloth laid flat on the ground, outward from every wall |
| Roof | The full run footprint — netting against hawks, or solid roofing over part of it for dry ground |
Space allowances follow the ranges published by US extension services and long-standing keeper practice. They are minimums for healthy birds, not targets — round up wherever you can.
The part other run calculators leave out: the ground
Every calculator will give you an area. Almost none will tell you what that area looks like after eight weeks of chickens on it, which is the thing people actually write to us about.
At the welfare minimum of 10 sq ft per bird, a static run becomes bare earth quickly, and bare earth becomes mud the first time it rains properly. That is not a failure on your part — it is arithmetic. Chickens scratch, dust-bathe and eat regrowth far faster than grass recovers, and the damage concentrates around the pop door and the feeder where they spend most of their time. Keeping actual grass under a flock needs either a great deal more space per bird or two runs used in rotation.
So plan for the ground you will really have. The approach that works in a normal backyard is a deep layer of coarse wood chips — not bark, not straw, not sand — topped up once or twice a year. It drains, it composts slowly, it gives the flock something to scratch through, and it turns the worst part of run keeping into the easiest. Grade the ground so water runs away from the coop before you put anything down; nothing you add on top fixes a run that sits in a dip.
Feet or metres — and why the run is the page where it matters
Coop plans travel badly between countries because timber comes in different lengths, but a run is just an area, a perimeter and a roll of mesh — so the numbers transfer cleanly. Switch the units above and everything on this page converts, including the buildable dimensions, which are rounded to sizes you can actually buy fencing for in each system.
A note on vocabulary, since it varies: chicken run is the usual term in the UK, Australia and New Zealand, pen and enclosure are used interchangeably, and in North America you will also hear chicken yard. They all mean the same thing — the fenced outdoor area attached to the coop.
Common questions
- How big should a chicken run be?
- Plan on at least 10 sq ft (about 1 m²) of run per standard hen, 6 sq ft for bantams. That is a welfare minimum, not a target — birds spend most of their waking hours out there, and run space is what stops the squabbling that coop space alone cannot. If the run is their only outdoor space, aim for 15–20 sq ft each and you will see the difference in feather condition and behaviour.
- How big a run do I need for 6 chickens?
- Six standard hens need at least 60 sq ft (5.6 m²) — for example 6 × 10 ft or 2 × 3 m. If they never free-range, 100–120 sq ft is much closer to comfortable. Add the coop footprint separately: the run figure is open ground, not floor area you have built over.
- Will grass survive in a chicken run?
- Not at the minimum size, no. At 10 sq ft per bird a static run becomes bare earth within weeks — chickens scratch, dust-bathe and eat the regrowth faster than grass recovers. Keeping grass needs either far more space per bird (on the order of 250+ sq ft each) or a rotation between two runs. The realistic plan for a normal backyard run is to stop fighting it: put down a deep layer of wood chips, keep it dry, and top it up.
- How tall does a chicken run need to be?
- Six feet (1.8 m) if you want to walk in, which makes cleaning and catching birds far easier. Chickens themselves only need enough headroom to stand and flap — 3–4 ft works, but you will be crouching for years. Cover the top whatever the height: hawks and owls are the predators most people forget, and a covered run also stays drier.
- Do I need hardware cloth for the whole run, or just the bottom?
- Half-inch hardware cloth to at least 3 ft up, then welded wire or netting above that is a common and defensible compromise — most ground predators work low, and raccoons reach through anything wider than half an inch. What you must not skip is the apron: 18 in of hardware cloth laid flat on the ground, outward from every wall. Diggers follow the wall down, hit the apron, and give up. Chicken wire keeps chickens in; it does not keep anything out.
- Is a chicken run the same as a chicken pen?
- In practice, yes. "Chicken run" is the usual term in the UK, Australia and New Zealand; "pen" and "enclosure" are used interchangeably, and in North America you will also hear "chicken yard". They all mean the fenced outdoor area attached to the coop, as opposed to free-ranging.
- Can a chicken run be too big?
- For the birds, no. For your fencing budget and your ability to predator-proof it properly, yes. A smaller run that is genuinely secure and covered beats a large one with gaps — most losses happen because a big run was too expensive to mesh properly. Build the secure run you can afford, then free-range under supervision on top of it.
Next: size the coop itself · predator-proofing the run · buildable coop plans with the run drawn to scale