Average Penis Size
What peer-reviewed science says — based on clinical measurements, not self-reported surveys.
Average Measurements at a Glance
Mean values from Veale et al. (2015) meta-analysis of 20 studies, n = 15,521 clinically measured men.
Source: Veale D, Miles S, Bramley S, et al. (2015). BJU International.
Erect Length Distribution
The distribution is approximately normal (bell curve). The majority of men fall between 12–15 cm (4.7–5.9 in) erect.
Distribution approximated from Veale et al. (2015). BJU International.
Full Reference Table
| Measurement | Mean (cm) | Mean (in) | SD |
|---|---|---|---|
| Flaccid length | 9.16 | 3.61 | 1.57 |
| Flaccid girth | 9.31 | 3.67 | 1.00 |
| Flaccid stretched length | 13.24 | 5.21 | 1.89 |
| Erect length | 13.12 | 5.17 | 1.66 |
| Erect girth | 11.66 | 4.59 | 1.10 |
SD = Standard deviation. Source: Veale D, Miles S, Bramley S, Muir G, Hodsoll J. (2015). Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15 521 men. BJU International, 115(6), 978–986.
Why Clinical Measurement Matters
The Veale et al. (2015) meta-analysis is the most robust study on this topic specifically because it excluded self-reported data. Self-reported studies consistently show inflated averages — typically 1–2 cm larger than clinically measured results.
The 20 studies included in the analysis used standardised measurement protocols: erect length was measured from the pubic bone to the tip (bone-pressed), with circumference measured at the midshaft.
Key insight
Roughly 95% of men have an erect length between 10.0 cm and 16.0 cm (3.94–6.30 in). Clinical conditions like micropenis are defined as erect length below 7 cm after hormone stimulation.
Erect Length Percentiles
| Percentile | Length (cm) | Length (in) |
|---|---|---|
| 5th percentile | 10.53 | 4.15 |
| 10th percentile | 11.24 | 4.42 |
| 25th percentile | 12.02 | 4.73 |
| 50th (median) | 13.12 | 5.17 |
| 75th percentile | 14.23 | 5.60 |
| 90th percentile | 15.21 | 5.99 |
| 95th percentile | 16.00 | 6.30 |
Derived from Veale et al. (2015) nomograms. BJU International, 115(6), 978–986.
Sources
- Veale D, Miles S, Bramley S, Muir G, Hodsoll J. (2015). Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15 521 men. BJU International, 115(6), 978–986. ↗
- Wylie KR, Eardley I. (2007). Penile size and the 'small penis syndrome'. BJU International, 99(6), 1449–1455. ↗
- Herbenick D, Reece M, Schick V, et al. (2014). Erect penile length and circumference dimensions of 1,661 sexually active men in the United States. Journal of Sexual Medicine, 11(1), 93–101. ↗
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