Men who are worried about the size of their penis may be reassured by a recent analysis, which set out to determine what is ‘normal'.

Penis size can be a major worry for some men. However until now, there has been no formal systematic review of penile measurements, and no attempts to create a graphical diagram - known as a nomogram - that shows the distribution of the size of an erect or flaccid penis.

UK researchers decided to attempt to create such a nomogram of penis size measurements across all races and ages.

They analysed 17 relevant studies, which involved over 15,500 males who had undergone penis measurements by healthcare professionals.

The resulting nomogram revealed that the average length of a flaccid penis was 9.16cm (3.6 inches), while the average length of a flaccid but stretched penis was 13.24cm (5.2 inches).

Meanwhile, the average length of an erect penis was 13.12cm (5.1 inches).

The nomogram also noted that the average circumference of a flaccid penis was 9.31cm (3.6 inches), while for an erect penis, it was 11.66cm (4.5 inches).

"We believe these graphs will help doctors reassure the large majority of men that the size of their penis is in the normal range. 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," commented Dr David Veale of King's College London.

Details of these findings are published in the journal, BJU International.