What Size Tank Does a Bearded Dragon Need?
Short answer: an adult bearded dragon needs at least a 4 × 2 × 2 ft enclosure (48 × 24 × 24 in), which is about 120 gallons. Babies can start in the adult enclosure with extra hides, or in a smaller tank for a few months, but they grow fast.
Tank size by age
| Age | Length | Minimum enclosure |
|---|---|---|
| Baby (0-3 months) | 3-10 in | 40 gallon (36 × 18 in) as a temporary setup, or the adult enclosure |
| Juvenile (3-12 months) | 10-18 in | move to the adult enclosure |
| Adult (over 1 year) | 16-24 in | 4 × 2 × 2 ft, about 120 gallons |
48 × 24 × 24 ÷ 231 = about 120 gallons
Why the old "40 gallon" advice is out of date
Older care sheets said 40 to 75 gallons was enough. Keepers and reptile vets now recommend at least 4 × 2 × 2 ft because a bearded dragon needs room for a real temperature gradient (a hot basking end and a cool end), for a long UVB tube, and to move and climb. Many keepers use a 4 × 2 × 2 ft enclosure or even 6 × 2 × 2 ft.
Setting up the enclosure
- Basking spot: about 100-110°F (38-43°C) for adults, measured on the basking surface.
- Cool side: about 75-85°F (24-29°C). Night: can drop to about 65-70°F (18-21°C).
- UVB: a T5 high-output UVB tube covering about two thirds of the length, mounted at the distance the maker recommends.
- Thermostat and thermometers on both ends.
- Substrate: tile, paper or a soil mix; avoid loose calcium sand.
- Furniture: a basking platform, branches, and at least one hide.
Glass tank or front-opening enclosure?
Both work. Front-opening PVC or wooden enclosures hold heat better, and opening from the front is less stressful than reaching in from above like a predator.
See enclosure sizes for other reptiles in the calculator below, and how long bearded dragons live in bearded dragon lifespan.
Sources: current keeper guidance (ReptiFiles, reptile societies); Association of Reptile and Amphibian Veterinarians husbandry advice.
Try the reptile tank size calculator
Enter your own numbers below, or open the full reptile tank size calculator with the formula and more examples.
This guide is general information, not veterinary advice. Your pet may differ: ask your vet. Terms
Frequently asked questions
Is a 40 gallon tank big enough for a bearded dragon?
Only for a baby, for a short time. An adult needs at least 4 × 2 × 2 ft, about 120 gallons.
Can a baby bearded dragon live in a big tank?
Yes, as long as it has hides and food it can find easily. Many keepers start babies in the adult enclosure.
What size tank does a bearded dragon need in gallons?
About 120 gallons (4 × 2 × 2 ft) for an adult.
Can two bearded dragons share a tank?
It is not recommended. Bearded dragons are solitary and housing them together often leads to stress and fights.