Which studies report 90th and 95th percentile erect penis lengths and what were their sample sizes?
Executive summary
Two sources commonly cited for erect penis percentiles are the 2015 systematic review by Veale et al., which produced nomograms from provider-measured studies and pooled 692 erect measurements (reporting percentile charts subsequently summarized in media), and later meta‑analyses that pooled far larger numbers of subjects but did not consistently publish 90th/95th percentile cutoffs; popular reporting translates Veale’s nomogram into a 95th‑percentile erect length of about 16 cm (6.3 in) [1] [2] [3]. Other large studies report mean erect lengths or broad ranges (including an Italian clinical study with n = 4,685 and mean erect 16.78 cm), but they do not always publish explicit 90th/95th percentiles [4] [5].
1. Veale et al. — the nomogram that anchors the percentiles
Veale and colleagues systematically reviewed provider‑measured penile dimensions and constructed nomograms for flaccid, stretched and erect length, explicitly pooling an aggregate of 692 erect measurements to model percentile curves that have been quoted by press accounts and secondary articles (Veale pooled n = 692 for erect length and produced nomograms) [1] [6]. Those nomograms, as interpreted in mainstream science reporting, place an erect length near 16 cm at the 95th percentile — a figure widely repeated in outlets such as Science and the Los Angeles Times [2] [3]. It is critical to note that Veale’s erect sample (n = 692) was much smaller than the pooled samples for flaccid and stretched measures, a limitation the authors themselves acknowledged [1] [6].
2. Media translation — how 95th percentile ≈ 16 cm entered public discourse
Science magazine and other outlets interpreted the Veale nomogram to state that an erect penis of approximately 16 cm (6.3 in) lies at the 95th percentile, meaning roughly five in 100 men would be larger [2]. The Los Angeles Times similarly reproduced the nomogram’s summary ranges — asserting that 95% of erect lengths fall between about 3.9 and 6.5 inches (≈9.9–16.5 cm), which maps the upper bound to roughly 16–16.5 cm [3]. Those media figures track back to Veale’s nomograms but are second‑hand numerical readouts rather than original per‑study percentile tables [1] [2] [3].
3. Larger meta‑analyses and clinical series — many more men, fewer explicit percentile cutoffs
More recent systematic reviews and meta‑analyses pooled far larger numbers of men but typically reported pooled means and ranges rather than explicit 90th/95th percentile cutoffs: a 2023 temporal meta‑analysis reported erect measurements across 20 studies with erect values ranging from 9.50 cm to 16.78 cm and a pooled sample of 18,481 men reporting erect length data across the literature it surveyed [5] [7]. A large Italian clinical series measured 4,685 men and reported a mean erect length of 16.78 cm but did not publish clear 90th/95th percentile cutoffs in the snippets available [4]. Thus, while larger datasets exist, they often stop short of publishing standardized percentile tables comparable to Veale’s nomograms [5] [4].
4. Why percentiles vary and why precision is limited
Variation in reported percentiles stems from methodological differences: many studies rely on self‑measurement (which skews larger), others use investigator measurement with different erection methods (natural vs. pharmacologic), and sample sizes for erect measurements are often much smaller than for flaccid or stretched measures — Veale explicitly excluded self‑reported measurements and required provider measurement but still pooled only 692 erect cases, a limitation the authors flagged [1] [6]. Meta‑analyses note socio‑cultural and logistic barriers to consistent clinical erection measurement, and reviewers caution that volunteer bias and heterogeneity across studies limit the certainty of high‑percentile cutoffs [5] [7] [8].
5. Bottom line and gap statement
The clearest, widely cited source for explicit percentile charts is Veale et al.’s nomogram (pooled erect n ≈ 692), which media outlets translate to a 95th percentile near 16 cm (6.3 in) [1] [2] [3]. Larger pooled datasets exist (total erect observations cited in later reviews up to ~18,481 across studies or individual large clinical samples such as n = 4,685 in Italy), but those analyses and single‑site studies most often report means and ranges rather than published 90th/95th percentile tables in the material summarized here [5] [4]. Given the documented limitations — small clinical erect samples, differing measurement methods, and self‑report bias — the 16 cm (95th) figure should be understood as a best‑available, media‑amplified interpretation of Veale’s nomograms rather than an immutable population constant [1] [2] [5].