Average penile length
Puberty and adolescence bring emotional and physical changes in both boys and girls. Teenage boys of 14 to 16 years of age are particularly interested in the sexual development of their growing bodies and seek information about the length, size and shape of their penis or testicles and scrotum. It is normal for teenage boys to compare their penis to that of their peers with the majority thinking their penis is smaller than that of their friends.
Teenage boys might find it embarrassing to discuss the length and shape of their penis with their parents or GP and might rely on information from their friends and peers. Perceptions among teenage boys of what constitutes a normal penis length are based on cultural or ethnic views which link penile size with masculinity and virility. These can cause some teenagers to feel inadequate, creating fear and anxiety of being seen in a changing room or at the urinal.
Penile size and length vary during puberty (on average from 11 to 18 years old) because boys grow at different rates and their penis and testicles do too. The penis will continue to grow until the age of 21.
If you are worried about the size of your penis, you should know that a flaccid (limp or soft) penis is smaller than an erect one, that being in a cold environment or being anxious will make your penis look smaller and you should measure your penis standing in front of a full-length mirror while having an erection. Do not measure your penis while looking down as it will always look smaller.
Another way to determine the length of your penis is to measure the stretched penis length or SPL. This is mostly used in adult men and measures the flaccid penis from the pubic bone to the tip of the stretched penis. The average size of the penis in adult men varies from 8.5cm to 10.5 cm (3-4 inches) when limp to 15cm to 18cm (6-7 inches) when erect (hard).
One study looking at the penile length of boys aged 13 to 15 showed that among teenage boys of different ages, their average penile length was similar to those of different ages but at the same stage of puberty.
Teenagers should be reassured that the length of their penis is as individual as they are and should be confident about their growing body.