One very commonly asked question that is often posted on Internet and social media, particularly by those new to reptile keeping, is the question of “which animal(s) should I get/or are suitable for which sized enclosures”? This will of course depend on many factors, including how much space one has, each species’ potential adult size, and perhaps most importantly, simply what animal or species one is most comfortable, able, and/or interested in keeping (i.e. a snake, lizard or gecko, turtle/tortoise, etc.). Each species also has its additional specific care requirements as well. Always remember to do your homework and research before purchasing or taking home any new animal, and do not make impulse purchases without forethought. With this said, here are some suggested species/animals (non comprehensive) that may be appropriately housed in the following mentioned enclosure sizes or equivalent sized accommodations (i.e. turtle/tortoise tables for chelonians, ExoTerra/ZooMed/Zilla enclosures, plastic or fiberglass enclosures for many snakes and lizards).
Less than 10 gallons or Similar/Equivalent: Not many reptiles or amphibian options can be housed in enclosures less than 10 gallons in dimensions. Perhaps African dwarf frogs, however.
10-15 gallons or Similar/Equivalent: Many hatchling/neonate to juvenile snakes (colubrids, smaller python and boa species), leopard, crested (tall), and many other gecko and smaller lizard species, Hatchling to juveniles of many other larger lizard species (agamids, chameleons, etc.), hatchling turtles and tortoises of many species. Also, many tarantulas, millipedes, and other commonly kept insects, arachnids, and invertebrates.
20-30 gallons or Similar/Equivalent: Adult colubrid snakes of many species (corn snakes, kingsnakes, milksnakes, hognose snakes, and others), adult smaller boa and python species (rosy and sand boas, some adult ball pythons, Children’s, Spotted, and other Antaresia pythons), Hatchling turtles and tortoises of many species, Pairs or multiples of many smaller gecko and other lizard species.
30-50 gallons or Similar/Equivalent: Adult lizards of many species (such as bearded dragons, uromastyx, blue tongued and other mid sized skinks, Ackies and other dwarf monitors), Smaller adult turtle and tortoise species (Russian, Hermann’s, Greek tortoises, Diamondback terrapins, box turtles), many species of snakes (some adult ball pythons, larger colubrids such as gopher/bull/pine snakes and rat snakes).
55 gallons and over (in general) or Similar/Equivalent: Larger lizards (iguanas, mid sized to large monitors, tegus), mid sized to larger and/or more active turtles and tortoises, dwarf caiman and all other adult crocodilians, Many adult mid sized to large pythons and boas (Boa constrictors, carpet pythons, blood/short tailed pythons, Burmese pythons, reticulated pythons, and other species).