Skip to main content
KBS_Icon_questionmark link-ico

Am I normal? An analysis of penis lengths

A new analysis on what's considered ‘normal’ for penis length and circumference in men, carried out by researchers at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) and South London and Maudsley NHS Foundation Trust (SLaM), was published today in the British Journal of Urology (BJU) International.

The study will inform clinicians dealing with Body Dysmorphic Disorder (BDD), a serious anxiety disorder relating to body image, and could help counselling of men worried about their size, or with investigations into how condom failure relates to penile dimensions. Before this research, there had been no formal systematic reviews of penile size measurements and no attempts to create a graphical diagram, or nomogram depicting the size distribution of a flaccid or erect penis, and researchers hope the new review will help to address the concern that some men have about their penis size, and help those who are so preoccupied and distressed they may even be diagnosed with BDD. 

“We believe these graphs will help doctors reassure the large majority of men that the size of their penis is in the normal range,” said Dr David Veale from the IoPPN, King’s College London and South London and Maudsley NHS Foundation Trust, and lead author on the research. “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.”

The nomograms created by the review recorded male penis size measurements across all ages and many races. It included 17 studies with up to 15,521 males who underwent penis size measurements by health professionals using a standard procedure.  They revealed that the average length of a flaccid penis was 9.16 cm, the average length of a flaccid stretched penis was 13.24 cm, and the average length of an erect penis was 13.12 cm. The average flaccid circumference was 9.31 cm, and the average erect circumference was 11.66 cm. There was a small correlation between erect length and the participant’s height. 

Dr Martin Baggaley, medical director at SLaM, 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.”

BDD occurs alongside Obsessive Compulsive Disorder (OCD) and a person with BDD may constantly compare their looks to other people’s, spend a long time in front of the mirror or avoid the mirror altogether, constantly conceal a perceived defect or feel anxious when around other people or in social situations.

This review was part funded by the National Institute for Health Research Maudsley Biomedical Research Centre at King’s and SLaM.

Paper reference: ‘Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15,521 men.’ David Veale, Sarah Miles, Sally Bramley, Gordon Muir, and John Hodsoll. Published in BJU International DOI: 10.1111/bju.13010

For further information contact Tom Bragg, Press Officer at IoPPN, King’s College London, on +44(0)2078485377 or email