In 2015, scientists measured more than 15,000 men's penises in an effort to find out what size is "normal".

Researchers at King's College London and a London NHS trust said they hoped the review would help address "the concern that some men have about their penis size" and aid people suffering from anxiety and distress.

They revealed that the average flaccid penis is 3.6ins (9.16cm) long, or 5.2ins (13.24cm) when stretched, and 3.7ins (9.31cm) in circumference.

Erect penises are 5.1ins (13.12cm) long on average and 4.5ins (11.66cm) in girth.


There is a "small" positive correlation between erect length and a man's height, the study found.

The research, published today in the British Journal of Urology International, covered measurements across all ages and many races.

It used 17 studies including up to 15,521 penis measurements carried out by health professionals using a "standard procedure".

Lead author Dr David Veale, from King's College London's Institute of Psychiatry, Psychology and Neuroscience, said the findings had been made into size charts.

"We believe these graphs will help doctors reassure the large majority of men that the size of their penis is in the normal range," he added.

"We will also use the graphs to examine the discrepancy between what a man believes to be their position on the graph and their actual position, or what they think they should be."

A graph showing the distribution of different penis lengths in the study.
A graph showing the distribution of different penis lengths in the study.

The analysis is also being used to help men who are being counselled because of worries about their size, or who suffer from Body Dysmorphic Disorder (BDD), a serious anxiety disorder relating to image perception.

Dr Martin Baggaley, medical director at the South London and Maudsley NHS Foundation Trust, said: "BDD causes a person to have a distorted view of how they look and they can spend an obsessive amount of time worrying about their appearance.

"This can include worries over their weight, specific parts of their body and, for men, the size of their penis.

"This can take over someone's life and cause a great deal of distress.

"Hopefully this new study will help reassure those many men who are concerned with their penis size and assist clinicians dealing with BDD."

The research may also be used for investigations into how condoms splitting or failing is linked to penis size.

This story is a republished version of a 2015 article.