The average is smaller than almost everyone guesses
15,521 men, measured by researchers rather than by themselves.
The largest pooled analysis measured 15,521 men across seventeen studies, and counted only measurements taken by a clinician — because self-reported figures run consistently and predictably high. The average erect length came to 13.12 centimetres, and the average erect circumference to 11.66.
The spread is narrower than the anxiety around it suggests. Roughly 68 per cent of men fall between about 11 and 15 centimetres, and under 3 per cent exceed 16. The clinical threshold for a micropenis is 9.3 centimetres stretched — a diagnosis that applies to about 0.6 per cent of men.