A common house gecko is a tiny animal — most adults are 3 to 5 inches including the tail — but it lives its life on vertical surfaces, so its enclosure should be chosen like a small section of wall and foliage, not a floor. A tall tank of at least 12 by 12 by 18 inches suits one adult, while 18 by 18 by 24 inches is a better long-term home that holds a real gradient of hiding places, a feeding station, and room for the gecko's surprisingly energetic night hunting.
Height and cover are the real dimensions
In houses across the tropics these geckos spend the day flat behind picture frames and inside leaf clusters, then emerge onto walls at night. Recreate that with vertical cork panels, upright branches, and layered artificial or live plants reaching the top corners, so the gecko can choose a daytime hiding seam at the height it prefers. A tall but empty tank is barely better than a small one: the usable size of the enclosure, from the gecko's point of view, is the area of covered vertical surface. Add a small feeding cup mounted high for powdered diet or tiny insects, and a shallow water dish below, while expecting most drinking to happen from misting droplets on leaves.
Escape-proofing a very small lizard
Size decisions for this species are inseparable from security. A house gecko can flatten itself through gaps that look impossibly narrow and runs up an opened door in a blink, so a fine-mesh lid, doors that meet flush, and sealed cable holes matter as much as the measurements. The larger 18-inch-wide option is often easier to keep secure in practice, because you can open one side for misting while the gecko hides on the other, instead of working inches from a startled animal in a narrow tank. Check the fit of every panel before the gecko goes in, not after the first escape.
Warmth, humidity, and placement
House geckos like warmth without a fierce basking spot: a gentle warm area in the low to mid 80s at one upper corner, created with a low-powered heat source on a thermostat, with the rest of the tank drifting toward room temperature. Daily light misting keeps humidity in a comfortable middle-to-high range and provides drinking droplets. Place the tank where evenings are calm and room lights dim on a natural pattern, because this is a creature whose whole active life happens while the household watches television and then sleeps — a tank beside a constantly slamming door will keep it hidden and unfed.
One gecko or a group?
A single enclosure of the sizes above is best planned for one gecko. Males are territorial and will fight in a space this small, and mixed groups breed readily, which turns a simple pet home into a population problem. If you keep more than one female together, step up the size again and multiply the hiding seams and feeding stations so no individual is ambushed at the only cup.
Since this gecko does most of its living overnight, a short written routine for misting and cup changes, shared through KinsLe's Family Sharing, keeps its care consistent even when the person who set it up is away.