There are two ways to identify the turtle's age. First, look at the belly spots of the turtle in the sky. Each belly spot has circular lines, each circle represents one year (some have two or no circles), and several circles represent how old, which is basically the case; Another way is to look at the carapace on the back (so-called thirteen hexagons). Each carapace also has circles, and the number of circles represents the age.

Generally, it is calculated by the number of concentric rings on the tortoise shell shield, and each 1 circle represents 1 growth cycle, that is, 1 year. The number of concentric rings on the shield, and then add 1 (the birth of the broken shell is 1 year), which is the age of the turtle. This method can only be more accurate when the concentric ring pattern of the tortoise shell is clear. For the old tortoise or the tortoise with ambiguous concentric ring pattern, only its approximate age can be estimated.

The growth of turtles is relatively slow. Under normal conditions, the growth rate of females is: the weight of the first-year-old turtle is about15g, the second-year-old turtle is 50g, the third-year-old turtle100g, the fourth-year-old turtle is 200g, the fifth-year-old turtle is 250-250g, and the sixth-year-old turtle is about 400g. Male turtles grow slowly, and the maximum sexual maturity is generally less than 250 grams.

The age is calculated by the number of concentric rings (growth rings) on the tortoise shell shield, and one ring is a one-year growth period. Of course, different turtle species, the clarity of ring marks and the existence of ring marks when hatching will also affect the accuracy of age. Turtles generally have a long life span, which can last for several decades. According to records, one kind of tortoise has a life span of more than 150 years, so it has the reputation of "a thousand-year-old tortoise and a thousand-year-old turtle".