The average length of a normal adult male penis is 9-12cm after erection, but an erect penis shorter than 9cm can only be described as short, not necessarily abnormal, as long as the erectile function is normal (to meet reproductive needs), that is normal. Penis development is influenced by many factors, mainly genetic factors and androgen levels, and generally the size of the penis is fixed after puberty. Theoretically, an erection of more than 8cm can meet the needs of women, so there is no need to be too obsessed with size. However, if there are problems such as erectile dysfunction, or lack of sperm vitality, you need to visit a regular hospital’s male department or urology department and treat the medication under the guidance of a doctor. The method of measuring the length of an erect penis is as follows: when the penis is fully erect, use a hard ruler and press it slightly against the pubic symphysis (i.e., the bone at the root of the penis), starting here and ending at the outer urethral opening of the glans penis, and the measured length is the erect penis length.