What is the average penis size in the general male population?
Executive summary
A clear consensus in peer-reviewed reviews and large meta-analyses places the mean erect adult human penis length at roughly 12.9–13.6 cm (about 5.1–5.4 in), with girth averaging around 11.7 cm (4.6 in) when erect; most high‑quality, clinician‑measured studies cluster in this range [1] [2] [3]. Differences between countries and races are small relative to individual variation, and methodological choices—self‑reporting versus provider measurement, sample selection, and how the fat pad is handled—explain much of the disagreement in popular figures [4] [1] [5].
1. What the best reviews actually say
Large syntheses that rely on provider‑measured data report average erect lengths near 13 cm: a prominent meta‑analysis combining 17 studies with 15,521 men reported an average erect length of 13.12 cm (5.16 in) and girth of 11.66 cm (4.59 in) [1], while clinical reviews and textbooks place the typical erect length between about 12.9 and 13.9 cm (5.1–5.5 in) [2] [3].
2. Why widely quoted higher numbers persist
Much of the public narrative that asserts a 6‑inch (15.2 cm) average comes from self‑reported surveys and media repetition; self‑measurement studies tend to overestimate length because of volunteer and reporting biases, while clinician‑measured studies give more conservative, consistent results [6] [7] [1].
3. Measurement matters — technique changes the answer
How investigators measure is decisive: erect length in rigorous studies is measured by pressing the suprapubic fat pad to the pubic bone and measuring to the glans, and girth is taken at the base or mid‑shaft; flaccid, stretched, and erect measures differ substantially and are reported separately in systematic reviews [4] [1] [5].
4. Variation, distribution, and what “average” conceals
While the mean sits around 13 cm erect, distributions are tight enough that extreme outliers are uncommon; pooled studies show ranges across cohorts from roughly 9.5 cm to 16.8 cm erect in different samples, underscoring substantial individual variation even as the global mean is stable [8] [1].
5. Geography, race, and the limits of headline claims
Country‑by‑country tables and popular websites highlight regional differences, but meta‑analyses find that regional and racial differences are small, heavily overlapping, and often confounded by sampling, measurement, and cultural selection effects—so population means do not predict any one individual’s size [9] [10] [5].
6. Temporal trends and unresolved questions
Some recent systematic work reports an increase in reported erect length over decades—one meta‑analysis found a 24% rise in mean erect length over 29 years after adjustments—yet authors flag confounders (changes in study methods, sample composition, obesity trends, environmental exposures) and call for cautious interpretation [11] [12].
7. Clinical and social context: why numbers matter
Clinically, normative values help identify conditions like micropenis or guide counseling, but social anxieties are amplified by misinformation: surveys show men tend to underestimate how far their size deviates from the mean and many health‑oriented websites and clinics can profit from exaggerated anxieties; measurement transparency and clinician counseling are recommended [2] [6] [7].
8. Bottom line for the general male population
The most reliable, clinician‑measured data put the average erect penis length at roughly 12.9–13.6 cm (about 5.1–5.4 in) with average erect circumference near 11.7 cm (4.6 in); apparent discrepancies above or below this range are largely explained by measurement technique, self‑report bias, and sample differences rather than dramatic biological divergence [1] [2] [3].