Is 20 cm big?
Yes — 20 cm (7.9 in) erect corresponds to the 99.998th percentile, roughly 1 in 59,000 men in the statistical model, so verified cases are exceptionally rare.
Very. 20 cm (7.9 in) erect corresponds to the 99.998th percentile — the normal model built on Veale 2015 predicts about 1 in 59,000 men at this size or above.
The arithmetic is stark. The clinician-measured mean is 13.12 cm with a standard deviation of 1.66 cm, putting 20 cm more than four standard deviations out. 16 cm already ranks in the top 4%; 20 cm adds four full centimeters beyond that. Measured samples of this size essentially never appear in the clinical literature; the tail is that thin.
Which raises a fair question about the internet’s apparent abundance of 20 cm men. Most of those reports fail on method. Bone-pressed measurement, where the ruler is pushed into the fat pad over the pubic bone, adds roughly 1 cm relative to the non-bone-pressed technique used in clinical studies. Add generous rounding and a self-reported 20 becomes a measured 18-and-change. The two methods are compared in BPEL vs NBPEL, and the correct protocol is in how to measure.
A genuine, properly measured 20 cm exists. It is simply one of the rarest results the distribution produces.