Tell the calculator how many birds you keep, standard hens, bantams, large breeds or ducks, and it works out the coop floor space, the outdoor run, roost bar length, nest boxes, and how much feed and water they get through. Already have a coop? Enter its size to see how many birds it really fits.
How much space chickens need
The calculator uses two levels. Minimum follows the figures poultry extension services commonly give: about 2 sq ft of coop and 8 sq ft of run for each standard hen, and half that for bantams. Comfortable doubles the coop space (4 sq ft per standard hen) and adds a little run, which is what we recommend if your birds spend long winters or wet seasons inside.
- Roosts: 10–12 inches of bar per standard hen (6–8 for bantams).
- Nest boxes: one for every 4–5 hens; they share happily and usually favour one or two boxes anyway.
- Ducks sleep on the floor, so they need floor space instead of roosts: the RSPCA suggests at least 4 sq ft per duck inside and 10 sq ft outside, and about twice that is more realistic (RSPCA).
- Large breeds such as Brahmas and Jersey Giants get more space in our figures; those numbers are our estimate, scaled up from the standard guidance.
A worked example
Six standard hens at the comfortable level need about 24 sq ft of coop (a 6 × 4 ft floor), a 60 sq ft run (roughly 10 × 6 ft), 6 ft of roost bar and 2 nest boxes. Between them they eat about 1.5 lb of feed a day and drink about ¾ gallon, double that on hot days.
Before you build
- Plan where everything goes with our coop layout guide.
- Ventilation matters as much as floor space: see the non-negotiable ventilation guide.
- Ready to build? Start with how to build a coop from scratch and the materials and cost breakdown.
These calculators give general guidance from extension services and experienced keepers. Your breed, climate and setup may need more. For sick or injured birds, contact a poultry vet.
Frequently asked questions
How big should a chicken coop be for 6 chickens?
At least 12 sq ft of floor for six standard hens, and about 24 sq ft if you want them comfortable, plus a run of 48–60 sq ft. Bantams need roughly half that.
How many nest boxes do I need?
One for every 4 to 5 hens. Adding more rarely helps: hens tend to pick a favourite and queue for it.
How much roost space does a chicken need?
About 10 to 12 inches of bar per standard hen, and 6 to 8 inches per bantam. In cold weather they squeeze up; in summer they spread out.
Do ducks need a coop like chickens?
Ducks need a secure house for the night, but they sleep on the floor, so floor space matters more than roosts. Plan at least 4 sq ft per duck inside and a run of 10 sq ft or more each, with about twice that being more realistic.
Is my information stored?
No. Everything is calculated in your browser, and nothing you type is saved or sent anywhere. The share link keeps your numbers in the part of the web address after the # sign, which browsers do not send to the website.