Men who are overly concerned with their penis size may be suffering from body dysmorphic disorder — or the condition of believing that one’s appearance is defective and needs to be fixed or altered in some way. While the condition is common among women who worry they’re not skinny enough, inspiring some to turn to plastic surgery, men can have similar thoughts towards their genitals.

In a new study, published in BJU International, researchers from the UK wanted to examine what is considered “normal” when it comes to penis length and circumference, as well as the relationship between condom failure and penis size. The authors state that because there have been no formal or official reports about the topic, men are often left confused and concerned about whether they’re small or normal, either flaccid or erect. Additionally, they added there have been "no attempts to create a graphical diagram, or nomogram, that depicts the distribution of the size of a flaccid or erect penis."

The researchers analyzed medical literature and found 17 studies examining up to 15,521 males and their respective penis size, hoping to create a nomogram of male penis size measurements across all ages and races. The researchers averaged out the numbers, finding that the average length of a flaccid penis was 9.16 centimeters (3.6 inches), a flaccid stretched penis was 13.24 cm (5.2 in), and an erect penis was 13.12 cm (5.1 in). The average circumference of a flaccid penis was 9.31 cm (3.6 in), and that of an erect one was 11.66 cm (4.5 in).

The authors hope their charts will comfort and reassure men who don’t know where they stand when it comes to the average penis length.

“We believe these graphs will help doctors reassure the large majority of men that the size of their penis is in the normal range,” Dr. David Veale of King’s College London, an author of the study, said in the press release. “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.”

Source: Veale D, Miles S, Bramley S, Muir G, Hodsoli J. “Am I normal? A systemic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15,521 men.” BJU International, 2015.