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How Big Should My Chicken Coop Be?

How Big Should My Chicken Coop Be?

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Whether you are buying a prefabricated chicken coop or building one, you will have thousands of questions. The most common question is, how big should a chicken coop be? You want to make sure you have ample room for your flock, but not too large. There is a science to making your chickens happy and healthy. But don’t worry, the math is simple when raising backyard chickens

How big should a chicken coop be

What A Coop Needs

Before we talk about chicken coop math, we should first identify what all should be in your chicken coop. Some prefabricated coops have all of these, and some don’t. And if you are designing your own, you should have a checklist of everything that you need. A coop is for sleeping, nesting, and getting out of bad weather. So you want to make sure that it has all of these things. 

  • Space for chickens to scratch around in the bedding
  • Nesting boxes
  • Perches
  • Ventilation
  • Doors for you to get in
  • And a small door and ramp for your chickens to get out

The easiest part of designing a coop is the entryways for you and the chickens. Everything else utterly depends on how many chickens you have. 

How Big Should My Chicken Coop Be?

To determine your coop size, you need to calculate how many sq ft per chicken. For smaller bantam, you will need about two sq ft per bird, and larger ones need three sp ft per bird. So each chicken needs 2-3 square feet of space to feel comfortable. 

Most new chicken owners start with three chickens. That is enough to provide you with about a dozen eggs per week. With three chickens, you will need 9 square feet of space for your coop alone. This does not include the run area for foraging, as that will be a much larger area per chicken. 

Making a coop that is smaller than this could cause fighting and conditions like in industrial chicken houses. Your chickens would be susceptible to mold, bacteria, respiratory infections, and parasites. 

But is bigger better? There are some advantages to making a coop slightly larger than what you need. If you ever decided to get more chickens, you would not have to upgrade to a larger coop. But if you make your coop too large, your chickens could have a hard time staying warm in the winter. 

Nesting Boxes

Nesting boxes are an essential part of a coop if you want to keep your eggs safe. The rule of thumb that most owners go by is having one nest per five chickens. But this isn’t always true. If you plan on adding more chickens, you will need to have the space to add more boxes. And if you have too many nesting boxes, your chickens might use them for roosting. Roosting in a nesting box is discouraged because chickens poop while they sleep, making for a bigger mess to clean. And even if you provide every chicken with a nesting box, you will still see them all crammed into one.

For a flock of only three, one nesting box should be sufficient. But there are a few things to look for when installing nesting boxes. 


Most people raising backyard chickens love to use metal or plastic chicken coops. You can buy premade nesting boxes, or make some out of cat litter containers or milk crates. You will want your nesting box to be a material that is easily cleaned and non-porous. Chickens love to make a mess, and wood tends to be hard to clean in these areas. 


The perfect sized nesting box should be at least 1 square foot on all sides. One square foot will give your chickens the comfortability, and it will prevent your eggs or chicks from falling out. 


And finally, you will want your nesting boxes to be placed 2-4 feet off the ground. Placing the nesting box higher allows for safety, comfortability, and cleanliness of the nest. 

Perch Requirements

Contrary to the common belief, chickens do not sleep in nests. Chickens are a prey animal and love to sleep up high away from predators. Inside of a coop, your chickens will need a perch to roost on. So thinking about how big a chicken coop should be, you should make sure it is long enough for a roost.

The typical roost needs to have at least 10 inches of space per chicken. So in our three chicken scenarios, that means your perch will need to be 30 inches long. Most times, you might find them all huddled together to keep warm. But if a pecking order starts to change, fights might start. So you will want to be sure that your roost has enough space to prevent injury. But what are roosts made from? 

There are two common answers that chicken owners have for this. And neither one is right or wrong; it just depends on what your chickens prefer. In some studies, when given the option, chickens preferred to perch on tree branches. As long as it is long enough and secure, there should be no problems with this. Plus, it can be free!

Other studies have shown that using 2×4’s with the flat side up is the best for chickens in colder climates. The thought behind this is that the chicken will be able to roost with their feet flat. And when they are cold, they can sit on their feet to prevent frostbite. In either case, as long as the roost is long enough, your chickens should take to it just fine. 


Ventilation is needed for several things in a chicken coop. 

  • Helps with smells and reducing ammonia
  • Keeps good air circulation in summer
  • Helps remove moisture from the air in winter

But how much ventilation should a coop have? The answer to this has more to do with your local climate than it does chickens you have. For mild climates, you will want at least 1 square foot of ventilation per 10 square feet of space. So in our how big should a chicken coop be scenario, we decided on 9 square feet for three hens.

That means that we would only need 1 square foot of ventilation. If you live in a hot climate, it is best to have as much ventilation as possible to create a gentle breeze. Some examples would be windows open along with ventilation. Or it could be making an open-faced coop with hardware cloth. 

Where you put these vents also depends on your area. You want them up high in cold climates so that drafts can’t get in. And you will want them lower for hotter climates of the south. But if you live in an area that has hot summers and cold winters, you will want a mixture of both vent locations. If you are building your coop, you can get outdoor shed vents that open and close to help regulate with the seasons. 

If you are buying a prefabricated coop, they will already have ventilation installed. But many people find that they have to make some minor adjustments to add more depending on their location. 

How To Make A Chicken Coop

Now that we have the math out of the way, you can start to build your chicken coop. When raising backyard chickens, often times the coop is harder to make than a run, but it can be effortless. There are thousands of free plans online that you can follow but adjusted to your flock size. Just follow these simple steps, and you are on the path to fresh eggs. 

  1. Decide on how many chickens you can accommodate. If space is not an issue, then you can choose a flock size for your egg and meat needs. But if you have a smaller yard, measuring for the coop and run area first will determine how many you can get. 
  2. Now that you have your flock size, you can determine how many sq ft per chicken that you need. Remember that’s 2-3 square feet per chicken. After you get this number, you have your basic blueprint for a coop. 
  3. Next, you should plan for where all doors, windows, and ventilation goes. You will need at least one entry for you and one smaller one for your chickens. Windows are great for added ventilation and keeping an eye on your flock so that you might want at least one. And remember, you will need at least 1-sqft of ventilation per 10-sqft of the coop placed according to your climate. 
  4. Once that is done, you can plan the inside. You will need to make a blueprint of where your nesting boxes go and how many, that’s one box per five chickens. And a roosting perch that has 10 inches of space per chicken. 
  5. Now your blueprints are ready! All that’s left if gathering the tools and putting it together! And don’t forget to make it predator-proof. 

If you are buying a prefabricated coop, you will only have to worry about whether your math adds up with your coop. And in some cases, like with Amish coops, they can be customized for you and your unique flock. 

How Big Is Your Coop?

Chickens are an easy hobby to get carried away with. How big chicken coop you need entirely depends on your flock size. But even a decently sized flock doesn’t need as much space as you think. With a little math, you can make a coop that will make raising backyard chickens a breeze. 

Below is a Pinterest friendly photo…. so you can pin it to your Backyard Chicken Board!!

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