Chickens will be happier and healthier if they are let out during the day to forage. At night, they need protection against predators, so they should be kept in a chicken coop or shelter. The proper size of the coop depends on how many birds you have, what size they are, and whether you let them out to forage during the day or keep them confined to the coop.
If the coop is too small, manure will build up quickly in it, and ammonia levels in the air can become quite high. This is not good for you or your chickens. Chickens will also tend to peck each other more, and they will be more subject to disease. It’s best to make sure your chickens have plenty of coop space.
Below, we give the minimum number of square feet needed per bird. To determine the what size your coop needs to be, multiple that number by the number of birds that you plan to house in the coop.
For heavy breeds, like Barred Rocks or Buff Orpingtons, if you let your chickens out to forage during the day, then the coop that you put them in at night should have at least 4 square feet of space per bird. Thus, a 4′ by 8′ coop would be adequate for about 8 birds.
If you keep your chickens confined to the coop at all times, then you should provide 10 square feet per bird. In this case, a 5′ by 10′ coop would be adequate for 5 birds.
For lighter breeds, like the White Leghorn, chickens that are allowed to forage outside during the day should have at least 3 square feet per bird, so a 4′ x 8′ coop could house 10-11 birds.
Chickens that are confined should be given at least 7 1/2 square feet of space, so a 5′ by 10′ coop would be big enough for about 6 chickens.
Bantams, being smaller, don’t need as much space per bird. This is one reason they are popular in backyard flocks. 2 square feet per bird is adequate if they are allowed daytime forage, so a 4′ by 8′ coop could house 16 bantams.
We recommend a minimum of 5 square feet per bantam if they are kept confined, so a 5′ by 10′ coop could contain 10 bantams.
For more information about raising chickens, see Storey’s Guide to Raising Chickens.