Fact check: What is the average penis size according to a 2020 medical study?

1. Why the 2020 Review Became a Reference Point — What It Actually Found

The 2020 review synthesized multiple studies and reported an erect-length range of 5.1–5.5 inches, noting a combined mean of 5.36 inches from ten studies where researchers measured erect penises and 5.11 inches from 21 studies reporting stretched flaccid measurements. The authors emphasized volunteer bias—men who agree to participate may not represent the general population—and recommended counseling for men who misperceive normal size. This review frames the baseline estimate used in many summaries and public discussions, and it explicitly challenges the inflated lay belief that the average is six inches or more ^{[1] [4]}.

2. Concordant Findings from Earlier Large Samples — Reinforcing the Mid‑Five‑Inch Average

Large-sample research conducted earlier supports the 2020 range. A 2014 study measuring 1,661 sexually active men reported a mean erect length of about 5.57 inches (14.15 cm) and a mean circumference around 12.23 cm, underscoring that measured averages cluster in the mid‑five‑inch region. That study also warned that self-reported measurements can be inflated because of social desirability, which explains some discrepancies between studies relying on self-report versus clinician measurement ^[2]. These converging results strengthen confidence that the true population average is nearer the 5–5.5 inch band.

3. Newer Meta‑Analysis and Temporal Trends — Is Size Growing on Average?

A 2023 systematic review and meta-analysis reported a pooled erect length of 13.93 cm (about 5.49 inches) and concluded that erect length has increased over the past three decades across several regions and age groups. This study suggests a modest upward trend when comparing older and newer datasets, but it does not overturn the 2020 review’s central claim: averages still cluster in the mid‑five‑inch range. The 2023 work highlights the importance of examining temporal and geographic shifts as well as methodological consistency when interpreting aggregate figures ^[3].

4. Outliers, Regional Studies, and Measurement Challenges — Why Some Studies Report Bigger Numbers

Some large national or regional samples report substantially larger means, such as a study of 4,685 Italian men reporting a mean erect length of 16.78 cm (about 6.6 inches). That figure diverges from most pooled estimates and illustrates how sampling frame, measurement technique, and population characteristics (height, BMI, age distribution) can drive differences. The 2020 review and other scholars caution that stretched flaccid versus erect measurement, self-measurement versus clinician measurement, and volunteer sampling produce nontrivial variation, so individual study results must be read in context ^{[5] [1]}.

5. Practical Takeaways — Counseling, Perception, and the Limits of Averages

Across the literature, two practical points recur: first, most men overestimate average size and many seeking penile augmentation have measurements within the normal range; second, penile size is poorly correlated with sexual function or partner satisfaction in reviewed studies. The 2020 review explicitly recommends counseling and education to correct misconceptions and reduce demand for unnecessary procedures. Taken together, the evidence supports a consistent, evidence-based message: the best population estimate for erect length centers on about 5.1–5.5 inches, with methodological and regional variability explaining most apparent discrepancies ^{[4] [1] [3]}.