Male penis 13 centimeters, in the state of weakness as well as erectile state is a normal situation, male penis length is not an absolute standard, in the case of normal sexual function, do not have to be too concerned. The development of the male penis is absolutely determined by congenital genetic factors, acquired environmental factors, etc. With the growth of age, the penis is also in the process of development, the adult male penis length is not an absolute standard, in general, the soft state in the 6cm or so are normal, the erectile state of 12cm or so are normal, the penis 13cm whether in the soft as well as the erectile state is a normal situation. In the case of not affecting sexual life, as well as normal sexual function, do not have to worry too much about the length of the penis, if the penis is too short, as well as sexual function is affected by the situation, you need to go to the hospital in a timely manner to the urology department for examination and treatment, and in daily life to develop good habits, moderate sexual life.