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Do Bearded Dragons Really Grow To The Size Of Their Tank?

Do Bearded Dragons Grow To The Size Of Their Tanks?

Will your bearded dragon stay small if you do not move it into a bigger tank as an adult? Is it okay to keep an adult bearded dragon in a smaller tank? There is a lot of misinformation regarding this issue that some owners tend to keep their beardies in small tanks in an effort to reduce their size.

Bearded dragons do not grow to the size of their tanks. Regardless if the tank is small or large, a bearded dragon should still grow into its adult size, which is approximately 16-24 inches. Keeping an adult bearded dragon in a small tank may contribute to the decrease in size of the bearded dragon.

In this article, we will discuss why it is not a good idea to keep your adult bearded dragons in a small tank. At the same time, we will talk about the appropriate size of the tank that you should get based on your beardie’s size and age. Read on to find out more.

Do Bearded Dragons Grow To The Size Of Their Tanks?

No, bearded dragons absolutely do not grow to the size of their tanks. If this is the case, then a bearded dragon that is housed in a 120-gallon tank should at least be 30-34 inches long. But there is still no record of this.

So far, the biggest bearded dragon, which is the German bearded dragon, is measured to be 26-28 inches. These bearded dragons are not another species of beardies.

Their breeders just intentionally bred them to be larger than other bearded dragons.

is a bearded dragon's growth related to tank size?
The German bearded dragons were bred to be large simply by matching the genetics of already bulkier bearded dragons.

The confusion regarding this question lies in the fact that some bearded dragons turn out to be smaller in their adulthood.

There is a saying that “bearded dragons will only grow to the size of their environment”, but this does not relate to the actual tank itself.

Of course, as your beardie grows, it needs more room, a larger space to bask, a bigger area to explore, and more spaces to hide.

If you do not switch to a larger tank, then its growth is inhibited by the fact that its current tank cannot provide its new needs, not because the tank is small.

In this study, it was found that bearded dragons are not part of the universality of indeterminate growth. This means that they have determined growth, and once they reach a certain age, they would have reached their maximum size.

Factors That Affect The Growth Of Bearded Dragons

Here are the factors that affect the growth of your bearded dragon that you may encounter if you keep it housed in a small tank as a juvenile or adult.

Keep in mind that a larger tank does not guarantee the growth of your beardies. It is only with proper care that they can reach their full size.


Obesity is rampant in adult bearded dragons. This is ironic, considering that as it grows, the frequency of feeding decreases. Baby bearded dragons can be fed 3-5 times a day, while adults are fed once a day.

Baby beardies can be closely monitored while they are in a small tank, and they have more than enough room to roam around and properly digest their food.

On the other hand, an adult bearded dragon that is in a small tank does not have enough space to exercise.

What ends up happening is the nutrients are stored as fat. Even though it was converted into energy, there is no room in the tank to use that energy, so your adult beardie just ends up staying in one place.

It may become fatter, but no amount of a balanced diet can make it larger in size.

Heating And UVB Lighting

Does a bigger tank cause a bearded dragon to grow bigger?

The ability to properly thermoregulate also plays a huge factor in the growth of a bearded dragon.

If they are housed in a small tank as adults, they cannot bask properly as probably the UVB may just be reaching some parts of its body.

As they grow bigger, they also need wider cool and hot spots to exhibit this thermoregulatory behavior. A small tank cannot provide this.

Your beardie cannot thermoregulate and develop its bodily systems if half of its body is warm while the other half is cool.

At the same time, the mixing of the two spots can affect their sleep cycle. When they do not have enough rest, they will not grow properly.

Need help with your dragon’s lights? We have created guides on the best UVB lights for bearded dragons here and the beast heat lamps for bearded dragons here.


Eating and burning energy is enough for baby bearded dragons, and they can do so in a small tank. As for adult beardies, they need further enrichment.

They need to be able to walk to their basking spot, hunt their feeders, and also walk to their water bowl.

The tank should be large enough to have enough space for them to explore but also put in enrichment objects like branches, hides, rocks, and plants.

Part of the growth of bearded dragons is to also stimulate them in order to decrease stress. If they are sedentary in a small tank, lack of stimulation inhibits growth.

Tank Sizes For Bearded Dragons

Here are the recommended size of tanks based on your bearded dragon’s age and size.

AgeSizeTank Size
0-3 months3-11 in.20-40 gallons (24″x18″x18″)
4-5 months9-16 in.40-75 gallons (48″x18″x18″)
6-8 months11-20 in. 50-75 gallons (48″x24″x24″)
12+ months16-24 in.75-120 gallons (60″x24″x24″)

Here are our recommendations for bearded dragon tanks so you do not have to cross-check the sizes based on your beardie’s age and size.

Why Do Baby Bearded Dragons Need A Small Tank?

do bearded dragons grow faster in a bigger tank?

Baby bearded dragons need to be housed in a small tank to make them feed easier. In a large tank, it will be difficult for them to catch their prey, and inevitably, doing so may result in injuries.

You can definitely hand-feed them, but this does not help them develop their hunting instincts and may also contribute to obesity. At the same time, giving baby beardies such a large space may stress them out.

Even though you provide a lot of hiding spots, the wide area may still make them feel too exposed.

If they do not feel secure, they will be anxious most of the time, which can also inhibit growth or lead to them getting sick easily.

If you need more information on bearded dragon care, check out our beardie care guide here!


Bearded dragons do not grow to the size of their tank. Rather, the increase in the size of the tank gives the owner the capacity to adequately provide for their needs.

There is really no way around it, as you should switch into a larger tank as your beardie approaches adulthood.

It may be seen as a hassle, but it will help ensure that your beardie is healthy and will grow to its proper adult size.

Pierre And The ReptileCraze Team
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