When I first adopted a bearded dragon, many experienced beardie owners advised me that keeping them in a large enclosure would help them attain maximum growth. When I researched, I found that no doubt, a spacious chamber is good not only for the growth but also for the overall health of bearded dragons. However, enclosure size is not the only factor; many other variables also impact the beardie’s growth.

As far as the question “Do bearded dragons grow to the size of their tank?” is concerned, it can be answered NO / YES. “NO” because bearded dragons are not able to attain the size of their chambers. In simple words, even if you place your bearded dragon in a considerably large enclosure, it will not grow indefinitely and will stop growing after achieving its natural size. “YES” because if bearded dragons are placed in a small chamber, it definitely hinders their growth, and they grow only to the size of their environment.

Why Do Beardies Grow To The Size Of Enclosure?

Naturally, many animals, including some fishes and bearded dragons, only grow in proportion to the space available in their surrounding environment. This behavior actually enables them to limit their growth to the size that better fits their environment and keeps them comfortable. Although many factors affect your beardie’s growth, it is imperative to use a chamber of appropriate size according to the size and age of your beardie. You must also ensure that hides are large enough for your bearded dragon to fit comfortably. Maintaining the appropriate size of chambers and hide is essential because these can impact the overall dimensions of your bearded dragon since they naturally shrink to fit in them.

What Size Tank Is OK For My Bearded Dragon? &  How Big A Bearded Dragon Can Grow?

As growth is a continuous process, choosing the right size tank from day one of your beardie’s life is imperative. Choosing the wrong size tank (or too small a tank) will impact his overall growth, and he may not attain his natural size. Yes, bearded dragons need tanks of different sizes during different phases of life. Most beardie owners generally prefer to arrange three tanks because usually, bearded dragons are categorized as a baby (0 – 6 months), juvenile (6 – 12 months), and adult (above 12 months). However, some experts and owners are of the opinion that since baby bearded dragons grow very rapidly, so they need two chambers during babyhood, one small tank during the initial few weeks of their lives and then a comparatively larger tank during the last days of babyhood.

So to help bearded dragon owners, we have created a chart that shows the growth, size, and weight of bearded dragons with age and the recommended size of the tank at their respective ages.

Age (months)CategorySize (inches)Weight (grams)Tank Size (gallons)
1Baby3 – 44 – 620 – 40
2Baby5 – 98 – 4020 – 40
3Baby8 – 1122 – 11020 -40
4Baby9 – 1241 – 11540 – 75
5Baby11 – 16102 – 11540 -75
6Juvenile11 – 18183 – 18850 -75
7Juvenile13 – 18230 – 28050 – 75
8Juvenile14 – 20252 – 32750 – 75
9 – 10Adult16 – 22280 – 36075 – 120
11 – 12Adult16 – 24350 – 46575 – 120
12+Adult16 – 24380 – 51075 – 120

Why Can’t I Place My Baby Bearded Dragon In A Larger Tank?

As mentioned above, a spacious tank positively influences the growth of bearded dragons, and a narrow tank can hinder their growth. You may ask, since my bearded dragon is growing rapidly, can I keep my baby beardie in an adult-size chamber from day one, and not spend money on 3 or 4 enclosures?

At the first thought, it may look like an attractive idea, but it’s not a good for a baby bearded dragon to be placed in an adult size chamber. Initially, when their hunting skills are not fully developed, catching the live food (or prey, like crickets, etc.) will be difficult for baby bearded dragons. In addition, you will have to bear the extra cost of heating and lighting a big chamber.

Why Bearded Dragons Need A Spacious Tank?

Bearded dragons need appropriate size tank as shown in table above because they are cold-blooded or ectothermic animals. The bodies of such animals can’t produce heat, and they always depend on external heat sources to get the necessary heat to carry on body function. At the same time, they also need a cool area where they can hide when they feel too hot.

So if the chamber is too small, it will heat up entirely, and there will be no cool spot for your beardie to hide. Soon your bearded friend will be heat-stressed and dehydrated, leading to many complications and even death.

Other Factors Affecting The Growth Of Bearded Dragon

Genetics

In bearded dragons, like any other living organism, the final color, personality, temperament, growth, and size are influenced by the genetic combination they receive from their parents. It is a factor guided by nature, and we have nothing to do with it. You can expect a too large or too big beardie from an average size pair of bearded dragons. So don’t be surprised if you see a huge difference in the size of two beardies from the same parents.

Gender

Another factor that is beyond our control and has a significant impact on the size a beardie may attain is gender. Size varies with gender in all animals, and obviously, the average size of male bearded dragons is 3-4 inches more than the average size of female beardies.

Feeding & Nutrition

After genetics and gender, the first factor that will decide the maximum size your bearded dragon can attain is its nutrition. In addition, nutrition is the first factor we can manipulate, and it is up to us to provide our bearded friends with a well-balanced and high-quality diet according to their age requirements. Bearded dragons are omnivores. However, there is a big difference in the nutritional requirements of baby and adult beardies. Baby bearded dragons need to eat 3 – 5 times daily, and 75 % of their diet must consist of animal protein (e.g., cricket or other insects). While adult beardies require only 25% share from insects, they are OK if fed once daily.

Heating & Lighting

Bearded dragons require 10 – 12 hours of high-quality UVA and UVB light. Light is necessary to absorb calcium and vitamin from the intestine. Both these nutrients are necessary for bone growth and development. If you are not providing sufficient light, they will not be able to process vitamin D and calcium. And a bearded dragon who is deficient in calcium will have weaker bones, be unable to walk and hunt, or can develop more complicated conditions like a metabolic bone disease.

Summary

Bearded dragon will stop growing after achieving its natural size regardless the size of a chamber. However, when placed in a too-small enclosure, it can instinctively restrict their growth to remain fit and comfortable in the available space. Therefore it’s crucial to provide them with an appropriate chamber (according to their age and size) to support their optimum growth. Placing a baby bearded dragon in a too-big tank is also detrimental. So it would be best if you stuck to the recommended sizes.