what age is considered an adult tortoise
As I understand it, it can take 7-10 years to become fully grown, depending on the environment, feeding, etc. They are considered an adult at 1 year of age, which is about 4 inches (10.1 cm). 12 cm for a 3 year old is a bit on the small side, I would expect a male at that age to be closer to 14 cm if not more.You should expect a male to reach 18-23 cm or more when full grown, a female 25-30.5 cm. JAX.osted: Tue Dec 15, 2009 11:52 pm. Technically, they're considered to be hatchlings until one year of age, then juveniles, later followed by sub-adults and adults (I think there's a phase in between there somewhere), so adulthood would be reached at about 5 years of age.