The length of a man’s penis can vary depending on age, region, ethnicity, race, and physical condition. Generally, the penis of an adult male over 18 years old is 4.5-11cm in length when in a weak state, with an average of 7.1cm, and can reach 10.7-16.5cm in length after erection, with an average of about 13cm. If the length is <8cm, it is generally considered that there may be shortening. The length of the penis of the same person is not constant, such as cold, tension, different methods of measurement, there can be different values. In fact, compared to the length, the hardness and the method and technique of sexual life are more important in sexual life. In women, the sensitive part of the vagina is in the outer 1/3 of the vagina, and the length of the vagina is about 9.5-10.5cm during sexual excitement, and 11-12cm during orgasm, so as long as the erection function is normal and the sex life can be completed normally, the length is normal.