Generally speaking, the length of male penis in the erect state is greater than 9cm is normal, and in the weak state is greater than 4cm is normal. The size of the male penis varies greatly, and is generally related to genetic factors and congenital development. As long as it is within this range, it is a normal penis size. In addition, there is a criterion that as long as the male penis does not affect the male to lead a normal sex life, also belongs to normal. If the penis is really too short and has seriously affected the patient’s urination or sex life, you need to go to the hospital for relevant examination and treatment in a timely manner, and if necessary, it is recommended that you can go for penis lengthening and thickening surgery.