How Old Is My Leopard Gecko? Age Guide
Why exact age usually can't be pinned down
Unless you hatched the egg yourself or have breeder records, there's no reliable way to determine a leopard gecko's exact age from appearance alone — growth rate varies with genetics, diet, and past husbandry. What you can do is place it into a life stage.
Rough stage indicators
Hatchling: under 3 months, very small, still developing pattern. Juvenile: 3–10 months, rapid growth, pattern maturing. Sub-adult: 10–18 months, growth slowing, sexing organs typically visible from ~5–6 months onward. Adult: 18 months+, full length reached, weight becomes the main variable left.
Breeding age matters more than a guess
Regardless of estimated age, females shouldn't be bred until they're both sexually mature and at a safe weight — commonly cited as roughly 45g and around a year old — since breeding an underweight or too-young female carries real health risk.
Use the interactive tool
The Leo Table's age calculator walks through size and development markers interactively to narrow down a likely age bracket for a gecko of unknown history.
See the full care guides guide, or browse all 593 info pages.
A single adult leopard gecko needs a 20-gallon long tank as an absolute minimum, with a 36x18 in (40-gallon breeder) footprint now considered the recommended standard — plus a secure lid, an under-tank heater on a thermostat, a thermal gradient, at least three hides, and a shallow water dish.
Set up in this order: substrate, then heat source wired through a thermostat, then hides and water dish, then decor — and run the whole enclosure for at least 24–48 hours to confirm stable temperatures before your gecko moves in.
Hatchlings can start in a 10-gallon tank or tub, juveniles do well in 20 gallons, and adults need a 20-gallon long as an absolute minimum — with 36x18 in (40-gallon breeder) now the widely recommended standard, not just an upgrade.
Heat a leopard gecko enclosure with an under-tank heater and/or overhead heat source (halogen or deep heat projector) wired through a thermostat — a thermostat is mandatory, not optional, and heat rocks should never be used.
Leopard geckos can survive without UVB using dietary D3 supplementation, but current husbandry guidance now recommends low-level UVB (roughly 2–6% T5) as best practice — it improves D3 synthesis, bone density, and natural behavior, and views on it have shifted significantly from older nocturnal-species advice.
Keep ambient humidity around 30–40% across most of the enclosure, with a dedicated humid hide raised to roughly 70–80% to support smooth, complete sheds.