Chicken owners have a lot of factors to consider in raising chickens, and the actual chicken coop size is often mysterious to new backyard chicken keepers.
Many commercially built coops do not provide enough feet per bird, ample roosting space, sturdiness, or weatherproofing to be optimal.
Different chicken breeds require different amounts of space; heavy breeds need more.
A chicken coop needs to be at least 3.5′ feet tall. You want your chicken coop to be tall enough to have room for the chickens to roost comfortably and not expose them to drafts; it will make them too cold during cold weather. Easy access to your coop’s interior is also a plus.
Look ahead for more details on how much space to provide your hens to keep them happy, healthy, and productive.
How Much Space Do My Chickens Need?
If your chickens are too cold, they might sleep in the nesting box, which dirties it up as they poop during their sleep.
The minimum height for a coop is 3.5′ feet tall on the lowest side of a sloped coop built for about 6 standard breed chickens.
This gives you roosting bars 12-20″ inches off the ground (chickens need to be able to walk under them, so higher is better), assumes about a 4″-inch layer of bedding, and accommodates 18″ inches of headroom between the top of the roosting bars and the bottom of the ventilation.
If your chicken is breathing heavily, poor ventilation may be the culprit; learn other reasons in our article at the link.
There should still be a good 5″ inches of ventilation on the shortest side of the coop.
A walk-in, taller coop, if you have the room and resources for it, is optimal for cleaning, collecting eggs, and checking chicken welfare.
If your chickens have a sizable outside run, you’ll need about 2-4′ square feet of interior floor space per chicken.
If you do not have enough exterior run space, you’ll need at least 4-5′ square feet per chicken to maintain a healthy flock.
The standard adult bird will need 8-10′ square feet of space outside the coop for stretching out, dust bathing, and foraging.
How High Does the Roost Need to Be?
Roosting bars need to be higher than the nesting boxes, or the chickens will sleep in the nesting boxes because they seek the highest place to sleep.
18-20″-inch-high roosting bars are one option or multiple sets of roosting bars at varying heights.
Your chickens need to be able to walk under the roosting bars.
Otherwise, you will lose floor space and need to build a bigger coop to avoid crowding and aggressive birds.
The natural roosting height in the wild would be about 4′ feet but remember they need horizontal space to access it and dismount, and heavy breeds such as Jersey Giants might injure themselves from up this high.
Providing a ramp with wooden strips for steps up to the roosting bar will help them access it.
Depending on the breed, you will need 6 to 10″ inches of roosting space per bird.
How High Do the Nesting Boxes Need to Be?
Nesting boxes need to be lower than the roost.
Some people feel nesting boxes need to be 2-3′ feet above the ground, but this is not true.
Floor level is good because they can’t roll eggs out and break them, and it is safer for chicks if they hatch them.
The downside of having them this low is you need to bend down further to gather eggs.
Stack nesting boxes if needed, giving your chickens more floor space.
Have 1 nesting box per 4-5 hens, at least.
A milk crate with clean straw makes an inexpensive nesting box.
Nesting boxes that extend from the coop and have a nifty roof on hinges enable you to easily reach in and get the eggs.
How Much Ventilation Does My Coop Need?
Coops need good ventilation to allow the ammonia and moisture generated by the manure to dissipate and allow fresh air to come in.
The minimum height above the roost you want your ventilation to begin above the roosting pole is 18″ inches.
You do not want your chickens exposed to drafts; they will get too cold, can get frostbite, and can even die during cold winters.
If your chickens move to the nesting boxes for warmth, they will get a lot of poop in them.
The amount of ventilation your coop needs will depend on how you manage cleaning your coop, how many chickens you have, how big the coop is, and the humidity where you live.
Daily cleaning requires less ventilation; the deep litter method will require much more ventilation.
If you use pine shavings or another organic material as bedding and composts as in the deep litter method, you will need more ventilation than sand.
Sand is inorganic and does not produce ammonia and other gases.
Some recommend 1′ square foot of ventilation per chicken or 10′ square feet of floor space.
A 4-6″-inch strip of ventilation across the top of two walls is a good idea; remember to make it high above your chickens’ roosting area.
Add ventilation to your coop by including small, screened windows in the walls, allowing for natural light and good for egg production.
Don’t be so attached to a coop you don’t provide a good home for your birds. Get a new one!
Related: How to reuse old chicken coops
What Else Should My Chicken Coop Have?
A taller coop provides easier access for cleaning.
Your chicken flock will need a freshwater supply and a feeding station, although some recommend waterers be outside to avoid additional moisture in the coop.
Choose your chicken coop bedding material carefully.
Wood shavings, straw, and sand are all good choices for different purposes and different floor options.
Related: Can you use hay for chicken bedding?
Installing electricity in your coop is convenient for using waterer heaters and a pop door (an automatic door that lets the chickens out in the morning and back in at night).
If you want to be able to move your chicken coop a couple of feet a day for forage and fresh grass, wheels are a must.
Related: Will chickens ruin my lawn and grass?
An elevated coop with legs makes it safer from chicken predators such as foxes, raccoons, or skunks, who dig holes through a dirt floor at night to get into the coop.
An elevated chicken coop also needs a solid floor panel to keep your chickens safe.
Most long-term chicken keepers make super high-quality chicken coops to spec or convert something like a garden shed to suit their purposes.
Using recycled materials is also popular, taking care with recycled wood and avoiding using chicken wire, which is useless against most threats to backyard chickens.
Further reading: How big of a chicken coop should you have for 10 chickens?