This chicken coop size calculator works out the coop floor area, run area, roost length and number of nest boxes your flock needs. Enter how many birds you keep and whether they are standard or bantam, and it applies the space guidelines backyard keepers commonly use. It helps first-time keepers buying a coop and anyone planning to add a few more hens.
If you leave a space field blank, the calculator uses commonly cited minimums for the bird size: standard birds 4 sq ft coop, 10 sq ft run and 10 in of roost each; bantams 2 sq ft, 5 sq ft and 6 in. Custom needs all three. A blank hens-per-box field uses 4. Birds kept in all winter, large breeds and mixed flocks do better with more room. Check local rules on flock size and coop placement.
How the Chicken Coop Size Calculator Works
Space needs scale almost directly with flock size, so the math is a set of simple multiplications. The chicken coop size calculator multiplies your number of birds by a floor-space allowance for the indoor coop, a larger allowance for the outdoor run, and a length of perch for roosting at night. Nest boxes are shared, so it divides the flock by the number of hens one box can serve and rounds up. Choosing standard or bantam sets typical allowances: if you leave a space field blank, the calculator uses the figure for that bird size, or you can type a larger number.
Formula: Coop area = Chickens × Coop sq ft per bird. Run area = Chickens × Run sq ft per bird. Roost length = Chickens × Roost inches per bird. Nest boxes = Chickens ÷ Hens per box, rounded up. Square metres = Square feet × 0.0929.
- Number of chickens — the most birds you expect to keep at once, including chicks you plan to raise.
- Bird size — standard large fowl such as Orpingtons and Rhode Island Reds, or bantams, which are roughly a quarter to a third the size.
- Coop space per bird — indoor floor area per bird, not counting nest boxes. Blank uses 4 sq ft (standard) or 2 sq ft (bantam).
- Run space per bird — fenced outdoor area per bird. Blank uses 10 or 5 sq ft.
- Roost per bird — inches of perch each bird needs to sleep side by side. Blank uses 10 or 6 in.
- Hens per nest box — how many laying hens share one box; 4 to 5 is the usual range, and if you leave it blank, it uses 4.
Example Scenarios
| Flock | Coop area | Run area | Roost length | Nest boxes |
|---|---|---|---|---|
| 6 standard | 24 sq ft (2.23 m²) | 60 sq ft (5.57 m²) | 5 ft | 2 |
| 3 standard | 12 sq ft (1.11 m²) | 30 sq ft (2.79 m²) | 2.5 ft | 1 |
| 8 bantams | 16 sq ft (1.49 m²) | 40 sq ft (3.72 m²) | 4 ft | 2 |
| 12 standard | 48 sq ft (4.46 m²) | 120 sq ft (11.15 m²) | 10 ft | 3 |
| 20 standard | 80 sq ft (7.43 m²) | 200 sq ft (18.58 m²) | 16.7 ft | 5 |
How Many Square Feet per Chicken? Tips for Planning Your Coop
The usual answer to how many square feet per chicken is 4 inside and 10 outside for standard birds, but treat those as floors, not targets. A coop size for 6 chickens of 24 sq ft works for birds that free-range all day; hens shut in through a snowy winter need more. Keep these points in mind:
- Plan for more birds. Most keepers add hens within a year or two. Size up now instead of rebuilding later.
- Measure usable floor only. Prefab coops often quote total footprint, including nest boxes and ramps. Measure the open floor yourself.
- Height matters. Roosts should be higher than nest boxes, or hens may sleep in the boxes and soil them.
- Use the chicken run size calculator result as a minimum. More run space cuts down on pecking, boredom and muddy ground.
- Nest boxes are shared. On how many nesting boxes per chicken, one box per 4 to 5 hens is enough; hens often queue for a favourite anyway.
- Ventilate. Good airflow near the roof keeps moisture and ammonia down without creating drafts at roost height.
The chicken coop size calculator gives a planning estimate. For designs and the history of poultry housing, see Wikipedia’s article on chicken coops. Many towns limit backyard flocks or ban roosters, so check local rules before you build.
Chicken Coop Size Calculator FAQ
How big should a coop be for 6 chickens?
For six standard hens, plan at least 24 sq ft of coop floor and 60 sq ft of run, with about 5 ft of roost and 2 nest boxes. If the birds are confined for long stretches in winter or you keep large breeds, add space. A 4 × 6 ft coop floor is a common size for six hens.Does the chicken coop size calculator work in meters?
Yes. You enter space per bird in square feet, and the results show both square feet and square metres for the coop and run. If you prefer to plan fully in metric, 1 sq ft is about 0.093 m², so 4 sq ft per bird is roughly 0.37 m² per bird.How much space do bantams need?
Bantams are much smaller, so a common guideline is about half the standard allowance: 2 sq ft per bird in the coop, roughly 5 sq ft in the run and 6 in of roost. Choose Bantam in the size menu to fill these in, then adjust if your bantams are especially active flyers.How many nesting boxes per chicken do I need?
One nest box for every 4 to 5 laying hens is usually enough, since hens lay at different times of day. Six hens need 2 boxes, twelve need 3. Roosters and young pullets that are not laying yet do not count. Boxes about 12 × 12 in suit most standard breeds.Are the guidelines different in the UK or Australia?
The space allowances used here are common backyard guidelines rather than legal rules in any one country. Some councils and welfare schemes set their own minimums for flock size, housing or commercial free-range birds, so check local regulations. The calculator shows square metres, which suits UK and Australian plans.How much run space does a chicken need?
About 10 sq ft per standard bird is a widely used minimum, so six hens need around 60 sq ft. More is better: crowded runs turn to mud, and bored hens peck at each other. If your birds free-range most days, a smaller run is fine as long as the coop is roomy.Related Calculators
Once you know the size of your flock, the livestock feed calculator estimates how much feed to stock. The fence calculator for posts and panels helps you price the run fencing, and the square footage calculator checks the floor area of an existing shed before you use the chicken coop size calculator to see if it fits.