The yellow-headed side-necked turtle is relatively large in size, with an average body length of about 40-50 cm in adulthood, and some large ones can grow to 60-70 cm. Different genders of yellow-headed side-necked turtles have different body shapes in adulthood. Normally, the female yellow-headed side-necked turtle will be larger, generally more than 60 cm. Males are smaller, rarely reaching more than 60 cm.

The cultured yellow-headed side-necked turtles are affected by environment and space, and their body sizes are also different. If there is enough room and food to keep them, their bodies will develop bigger. If the breeding environment is poor, then they will not grow very big.

The breeding time of the yellow-headed side-necked turtle has a great relationship with the breeding environment and mode. Generally speaking, the artificially bred yellow-headed side-necked turtle only needs 5-6 years to develop and mature. However, due to the different ways of feeding, their adult time is also different. Breeders can also judge whether they are mature by their size. If the female turtles are more than 60 cm in size and no longer grow for a long time, then they are mature. However, male turtles are small in size and generally do not grow to more than 60 cm, so breeders need to judge according to their age.