Vivarium Builder· UK sizes · 41 species
See your pet's perfect home,drawn to scale.
Pick a species and watch its enclosure build itself in 3D. Then test the viv you own — no tape-measure maths, no jargon.
Who's living here?
Bearded Dragon's home, drawn to scale
Floor space matters most — beardies are active ground-dwellers that need a full thermal gradient (40-42°C basking to ~25°C cool end).
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Minimum 120×60×60 cm·Recommended 150×75×75 cm
Showing 150 × 75 × 75 cm (4.9 × 2.5 × 2.5 ft)
Tap a size you own (or saw second-hand) — or drag the sliders. The box updates live.
Your build list
Everything a Bearded Dragon setup needs.
Skip the 40 open tabs.The complete Bearded Dragon setup — correct wattages, °C thermostats, UK stock — priced, vetted and on one list. Checked July 2026.See the kitVivarium & Enclosure Sizes by Species — UK Quick-Reference
Every figure below comes from our published species care guides and follows RSPCA and UK welfare guidance. Minimum is the smallest enclosure an adult can be kept in without compromising welfare; recommended is the size at which natural behaviour — thermoregulation, burrowing, climbing, full stretching — actually happens.
| Species | Minimum (cm) | Recommended (cm) | In feet |
|---|---|---|---|
| 120 × 60 × 60Our pick | 150 × 75 × 75Our pick | 4.9 × 2.5 × 2.5 ft | |
| 90 × 45 × 45Our pick | 90 × 60 × 60Our pick | 3 × 2 × 2 ft | |
| 45 × 45 × 60Our pick | 60 × 45 × 90Our pick | 2 × 1.5 × 3 ft | |
| 120 × 60 × 60Our pick | 120 × 60 × 60Our pick | 3.9 × 2 × 2 ft | |
| 120 × 60 × 60Our pick | 120 × 60 × 60Our pick | 3.9 × 2 × 2 ft | |
| 120 × 60 × 60Our pick | 120 × 75 × 75Our pick | 3.9 × 2.5 × 2.5 ft | |
| 60 × 45 × 90Our pick | 90 × 60 × 120Our pick | 3 × 2 × 3.9 ft | |
| 90 × 38 × 38Our pick | 120 × 45 × 45Our pick | 3.9 × 1.5 × 1.5 ft | |
| 120 × 60 × 30Our pick | 180 × 90 × 30Our pick | 5.9 × 3 × 1 ft | |
| 90 × 45 × 45Our pick | 120 × 60 × 60Our pick | 3.9 × 2 × 2 ft |
Tap any species to load it in the 3D calculator above. Invertebrate sizes (tarantulas, scorpions, mantises and more) are in the calculator — as a rule of thumb, a terrestrial tarantula needs a floor at least 3× its legspan in each direction.
How to measure a vivarium (and why floor space beats gallons)
Measure the internal length, depth and height in centimetres — external measurements steal 2-4 cm of liveable space to timber and glass. Ignore gallons entirely: volume tells you almost nothing about welfare. A tall, narrow 40-gallon tank and a long, low one hold the same water but offer a ground-dwelling gecko completely different lives. For most reptiles, floor area is the welfare currency; height only matters for arboreal species like crested geckos and chameleons.
Buying second-hand? UK listings usually quote "3ft" or "4ft" vivariums — that's the length. Tap the matching preset in the calculator above and you'll see instantly whether the bargain is actually big enough for your species.
Minimum vs recommended: what UK welfare guidance says
Under the Animal Welfare Act 2006, you have a legal duty to provide a suitable environment — and an enclosure that prevents a full thermal gradient or natural movement fails that test. The RSPCA publishes per-species guidance (our data follows it), and the modern UK keeping community has pushed standards up: 4×2×2 ft is now widely treated as the bearded dragon floor, not the ceiling. When in doubt, go bigger and furnish it well — no animal has ever suffered from too much well-designed space.
Vivarium, terrarium or tank — what's the difference?
In UK usage: a vivarium is the wooden, front-opening enclosure that holds heat well (ideal for bearded dragons, snakes and skinks); a terrarium is the glass, often taller enclosure that handles humidity and visibility better (crested geckos, chameleons, inverts); and a tank usually means an aquarium — only right for fully aquatic species like axolotls. The calculator labels each species with the type it actually needs.
Frequently asked questions
What size vivarium does a bearded dragon need?
An adult bearded dragon needs a minimum of 120 × 60 × 60 cm (4 × 2 × 2 ft), with 150 × 75 × 75 cm recommended. Floor space matters most — beardies need a full thermal gradient from a 40-42°C basking zone to a ~25°C cool end.
Is a 3ft vivarium big enough for a bearded dragon?
No. A 3ft (90 cm) vivarium is below the UK welfare minimum of 4 × 2 × 2 ft for an adult. It cannot hold a proper temperature gradient. A 3ft viv is only a temporary home for a juvenile.
What size vivarium does an adult royal (ball) python need?
At least 120 × 60 × 60 cm (4ft). UK guidance: the enclosure length plus depth should be at least the snake's length so it can fully stretch. Two snug hides and a soak-sized water bowl are essential.
What size tank does an axolotl need in litres?
One adult axolotl: 90 cm / 120 litres minimum, 200 litres for a pair. Water must stay 16-18°C — most UK homes need a chiller in summer. Fine sand only; gravel causes fatal impaction.
How big should a corn snake's vivarium be?
An adult corn snake needs a 120 × 60 × 60 cm (4ft) vivarium minimum — length plus depth should match or exceed the snake's length. They climb more than expected, so usable height is a bonus.
Can a vivarium be too big for a snake or gecko?
For adults, almost never — if it's well furnished. Hatchlings and shy species can feel exposed in big bare spaces; the fix is more hides and cover, not a smaller enclosure.
Guidance only — sizes follow our published care guides and RSPCA/UK welfare guidance. Bigger is always better; these are minimums, not targets.