What did the 2015 Veale et al. systematic review report as mean and median erect penis length?
Executive summary
Veale et al.’s 2015 systematic review reported a pooled mean erect penile length of 13.12 cm (standard deviation 1.66 cm) from 692 clinically measured erect penis observations, and built nomograms to show the distribution of sizes [1]. The paper emphasized that nomograms — including median/percentile information — were constructed, but the sources provided here do not explicitly state a single numeric “median erect length,” so reporting focuses on the published pooled mean and the study’s own caveats about erect-data limitations [1] [2].
1. What the Veale et al. paper actually reported: the pooled mean and sample size
Veale and colleagues conducted a systematic review and pooled data to create nomograms for flaccid, stretched and erect penile length and for circumference, and for erect length they report a pooled sample of n = 692 with a weighted (pooled) mean of 13.12 cm and pooled standard deviation of 1.66 cm [1]. The mean is the central numeric claim most media and secondary summaries quoted; the authors used pooled means and simulated observations from the normal distribution to derive their nomograms [1].
2. Median vs mean: what the paper provided and what the available reporting shows
The study’s principal output was nomograms — graphical depictions of percentile distributions — rather than a single emphasized median value; the paper reports 50th-percentile values for some measures (for example, the 50th percentiles for flaccid and stretched lengths in related reporting) and constructs percentile tables/plots, but the snippets available here do not include a clearly cited numeric “median erect length” in isolation, so the pooled mean (13.12 cm) and SD (1.66 cm) are the explicit central tendency measures provided in the accessible summaries [1] [3]. The authors’ approach therefore supplies both mean/SD and percentile-based nomograms, but the median for erect length is not reproduced in the extracted passages available to this report [1] [3].
3. Study strengths, limitations and alternative estimates
Veale et al. combined many studies to reach large cumulative samples for flaccid and stretched measures and produced clinical nomograms intended to reassure patients and guide clinicians, but they warned that relatively few erect measurements were collected in a clinical setting and erect-sample heterogeneity was a limitation [2] [1]. Independent subsequent meta-analyses have produced slightly different pooled means (for example, another review reported an erect mean around 13.84 cm in a larger pooled sample), illustrating that estimates vary with inclusion criteria, measurement methods and sample size [4]. Veale’s mean of 13.12 cm remains among the commonly cited, rigorously derived figures because it was based on clinician-measured data and explicitly constructed nomograms [1].
4. How to interpret the numbers in context
The Veale et al. figures are pooled averages across disparate populations and measurement protocols, with erect measures particularly scarce relative to flaccid and stretched measures; as the authors note, measurement context (clinical setting, method of erection induction or stimulation) introduces variability, and nomograms are meant to show distribution rather than to single out any one “normal” value [1] [2]. For those seeking a single summary statistic, the defensible answer from Veale et al. is the pooled mean erect length = 13.12 cm (SD 1.66 cm) from n = 692; the explicit median (50th percentile) for erect length is included in the paper’s nomograms but is not directly quoted in the accessible excerpts used here [1] [3].