What is the average penis size?
The average erect penis is 13.12 cm (5.16 in) long and 11.66 cm (4.59 in) in circumference, based on clinician-measured data from up to 15,521 men (Veale et al., 2015).
The average erect penis is 13.12 cm (5.16 inches) long and 11.66 cm (4.59 inches) around. The figures come from Veale et al. (2015), a systematic review pooling clinician-measured studies of up to 15,521 men. That measurement method is the whole reason to trust them: a professional with a ruler doesn’t round up the way a man filling out a survey does, which is why self-reported numbers always run larger than the clinical ones.
Flaccid length averages 9.16 cm (3.6 in), but it tells you almost nothing about erect size — the two correlate weakly. Stretched length, at 13.24 cm (5.21 in), is the better proxy and tracks erect length closely. Spread out, about 90% of men land between roughly 10.4 and 15.9 cm (4.1–6.2 in) erect, a band tight enough that most measurements sit within an inch or so of the mean. See the full statistics and methodology for the underlying data.