Which major 2015-2025 meta-analyses measured adult penis length and girth across countries?
Executive summary
Three major meta-analyses published or posted between 2015 and 2025 provided broad, cross‑country measurements of adult penile length and/or girth: "Worldwide Temporal Trends in Penile Length" (meta‑analysis pooling flaccid, stretched and erect lengths) [1] [2] [3], a 2024–25 China‑focused meta‑analysis comparing Chinese men to global data [4] [5], and a 2024–25 systematic review that pooled length and circumference by WHO region ("Who has the Biggest One?") [6] [7] [8]. Each used different inclusion rules and geographies, producing pooled means such as global erect length ~13.9 cm [2] and region‑grouped girth/length estimates reported by the WHO‑region meta‑analysis [9].
1. A global time‑trend meta‑analysis that set the benchmark
Veale et al.’s "Worldwide Temporal Trends in Penile Length" is the principal global meta‑analysis cited repeatedly: it pooled flaccid (8.70 cm), stretched (12.93 cm), and erect (13.93 cm) means and analysed changes over decades, reporting that erect length rose significantly over time after adjustment for age and region [2] [3]. The study followed PRISMA methods and is presented in full in WJMH and on PMC [1] [3]. This paper is the clearest single meta‑analysis spanning many countries and provides the commonly cited global summary figures used in subsequent reviews [2].
2. Regional WHO‑groups meta‑analysis that added girth and new country‑group comparisons
A later systematic review and meta‑analysis grouped measurements by WHO region and explicitly pooled both length (flaccid, stretched, erect) and circumference (girth). The authors reported pooled sample sizes (e.g., flaccid length n≈28,201; stretched n≈20,814; erect n≈5,669; flaccid circumference n≈30,117; erect circumference n≈5,168) and regional differences such as larger stretched means in the Americas and regional variation in circumference [9] [6]. That study used PubMed/Embase/Scopus/Cochrane through Feb 2024 and applied PRISMA standards [6] [7]. The paper highlights measurement heterogeneity and lack of standardization as a major limitation [6].
3. National‑focus meta‑analysis: China in a global context
C. Wang et al. produced a China‑specific meta‑analysis that included 23 Chinese studies (34,060 men) and compared them to international studies (15,216 men) to build nomograms; it reported Chinese means (erect ~12.42 cm; erect girth ~10.75 cm) and an unusually large "growth coefficient" from flaccid to erect in Chinese samples versus a global average (67.39% vs 43.45%) [4] [5]. The paper excluded certain East/Southeast Asian studies to control confounding and provides a deep look at one large national dataset in the global context [4].
4. What these meta‑analyses agree on — and where they diverge
Agreement: all three efforts emphasise that measurements depend heavily on study method, arousal state, and region, and that pooled erect means fall in the ~13–14 cm range rather than the larger self‑reported values circulating online [2] [3] [9]. Divergence: the WHO‑region meta‑analysis explicitly pooled circumference by WHO region and reported different regional rankings and larger sample counts for girth [9], while the China meta‑analysis focused on within‑country nomograms and proportional growth on erection that the global analyses did not emphasize [4]. The global time‑trend study emphasised temporal increase in erect length; the WHO‑region paper highlighted geographic variation and girth [2] [9].
5. Methodological limits readers must know
All three papers warn that differences in measurement technique (flaccid vs stretched vs erect; base vs mid‑shaft circumference), volunteer/self‑report bias, age and population selection, and lack of a single global standard introduce heterogeneity and potential bias [6] [3] [10]. The WHO‑region meta‑analysis explicitly calls out lack of standardized measurement as a "serious limitation" [6]. The China meta‑analysis excluded some regional studies to control confounding, a choice that changes comparability [4].
6. How journalists and clinicians should use these numbers
Use pooled figures as approximate, clinically relevant benchmarks (e.g., erect mean ≈13.9 cm from the global meta‑analysis) rather than definitive national rankings; apply regional or national nomograms when available [2] [4] [9]. Note that the WHO‑region meta‑analysis provides the most detailed regional circumference data to date, while Veale et al. remains the best source for temporal trends [9] [2].
7. Missing or contested items in current reporting
Available sources do not mention a single, multi‑country individual‑level dataset that simultaneously and uniformly measured length and girth across dozens of countries under identical protocols; instead, the meta‑analyses compile many smaller studies with varying methods [3] [6]. Claims of much larger global samples or photographic‑validation across 120 countries (appearing on non‑peer sites) are not supported by these peer‑reviewed meta‑analyses in the provided reporting [11] [12].
Sources cited: Veale et al. "Worldwide Temporal Trends..." (WJMH/PMC) [1] [3] [2]; Mostafaei et al. "Who has the Biggest One?" WHO‑region meta‑analysis [6] [7] [8] [9]; Wang et al. China meta‑analysis [4] [5].