What do large meta-analyses list as the 90th and 95th percentile erect penis lengths?
Executive summary
Two large, investigator-measured meta-analyses and their downstream summaries place average erect penile length in the low-to-mid 13 cm range and cluster the 90th percentile around ~15.2 cm and the 95th percentile around ~16 cm–16.4 cm; exact figures vary with the study sample and statistical method used [1] [2] [3] [4] [5].
1. What the big meta-analyses report on average erect length
A commonly cited pooled estimate from Veale and colleagues based on clinical measurements reports a mean erect length of 13.12 cm with a pooled standard deviation of 1.66 cm (n for erect = 692) and constructed nomograms from simulated distributions [1] [2]. More recent, larger systematic meta-analyses that combined many studies report similar mean erect lengths in the 13.8–13.9 cm range: one global meta-analysis pooled erect-length data and reported a mean erect length of ≈13.84 cm (SE 0.94) across 5,669 men [5] while another temporal meta-analysis gave a pooled erect mean of 13.93 cm (95% CI 13.20–14.65) [6] [7].
2. How the 90th and 95th percentiles are derived (and the numbers)
Using the Veale mean and pooled SD (mean 13.12 cm, SD 1.66 cm), the 90th percentile (mean + 1.2816·SD) computes to ≈15.25 cm and the 95th percentile (mean + 1.645·SD) to ≈15.85 cm; Veale’s published nomogram and simulated distribution also place the upper 95% bound near 16.44 cm, yielding widely quoted summaries that “a 16‑cm erect penis is roughly the 95th percentile” [1] [2] [3]. Independent reporting based on pooled data similarly cites an approximate 95th‑percentile value of ~16.0 cm [4].
3. Cross‑study consistency and why reported percentiles cluster
Different meta-analyses — despite variations in included studies, eras, and geography — converge on mean erect lengths ~13–14 cm and consequently place the upper percentiles in a narrow band around 15–16.5 cm; for example, Veale’s nomograms, the AAAS summary, and later global reviews all land the 95th percentile at roughly 16 cm [1] [2] [4] [5]. That clustering stems from modest pooled standard deviations (around 1.5–2.0 cm) in clinical measurements and the central limit behavior of large pooled samples [1] [2] [6].
4. Important caveats: measurement, sampling, and statistical choices
Percentile estimates depend on how length was measured (investigator-measured erect versus self-reported), which populations were included or excluded (studies typically excluded men with congenital anomalies, prior penile surgery, or erectile dysfunction), and whether meta-analysts used simulated normal distributions or empirical percentiles; Veale notes limited clinical erect measurements and uses simulation to produce nomograms, while larger pooled studies report pooled means with standard errors but not always pooled SDs needed for exact percentile conversion [1] [2] [5] [6]. Geographic variation, study era, and selection biases (clinical volunteers versus population samples) also shift means and SDs modestly, so a single percentile figure should be read as an approximate range, not an absolute cutoff [5] [6].
5. Plain‑language takeaway
Large, investigator‑measured meta-analyses consistently indicate that an erect penile length of about 15.2 cm corresponds roughly to the 90th percentile and that thresholds near 16–16.4 cm correspond to the 95th percentile; variability across studies and methods means these should be cited as consensus ranges rather than precise universal values [1] [2] [3] [4] [5].