The average erect penis is about 5.1 inches (13 cm) long.
Answer: FACT
The Veale 2015 meta-analysis of 15,521 men (clinician-measured) found an average erect length of 13.12 cm (5.17 inches). The 2025 WHO Regions meta-analysis found 13.84 cm.
Fact or Fiction Quiz
Test your knowledge — 20 statements about penis size, erections, and sexual health. Can you tell fact from fiction?
All Questions & Answers
Men with bigger feet have bigger penises.
Answer: FICTION
Shah & Christopher (2002) measured 104 men and found NO statistically significant correlation between foot size and penis size. This myth has been thoroughly debunked.
Penis size has been getting larger over the past 30 years.
Answer: FACT
A 2023 meta-analysis in World Journal of Men's Health found erect penile length increased 24% over 29 years (1942-2021). Possible causes include improved nutrition, earlier puberty, and endocrine disruptors.
Most women say length matters more than girth.
Answer: FICTION
In a landmark study, 90% of women (45 out of 50) reported that WIDTH was more important than length for sexual satisfaction (Eisenman 2001). Multiple studies confirm girth is valued more.
You can predict penis size from hand size.
Answer: FICTION
Multiple studies have found no significant correlation (r=0.01) between hand size and penis size. The digit ratio (2D:4D) shows only a very weak correlation (r=-0.12) with penile length.
Smoking can cause your penis to shrink.
Answer: FACT
Smoking damages blood vessels and causes atherosclerosis in penile arteries. A 1998 Boston University study found that smokers had measurably shorter erect length due to vascular damage, and smoking is a leading cause of erectile dysfunction.
Penile extender devices have been clinically proven to increase length.
Answer: FACT
Clinical studies (Gontero 2009: +2.3cm flaccid, +1.7cm stretched; Nikoobakht 2011: +1.7cm flaccid/stretched) have shown measurable gains. However, ERECT length gains were NOT directly measured in most studies. RestoreX (Mayo Clinic) showed +1.5cm in Peyronie's patients. Gains are modest (1-2cm) and require months of daily use.
Viagra and Cialis increase penis size permanently.
Answer: FICTION
PDE5 inhibitors improve erection QUALITY (hardness, duration) by keeping blood in the penis longer, but they do NOT increase the actual dimensions of the penis. No pill can permanently increase size.
Babies can get erections in the womb.
Answer: FACT
Fetal erections have been documented on ultrasound as early as 16 weeks gestation. They are reflexogenic in nature and are a normal part of development.
The average man gains about 4 cm going from flaccid to erect.
Answer: FACT
On average, men gain about 4 cm from flaccid to erect state. However, "growers" (26% of men) gain >4cm while "showers" gain <4cm. Flaccid size is a poor predictor of erect size.
Losing weight can make your penis look bigger.
Answer: FACT
Every 30-50 lbs of excess weight buries approximately 1 inch of penile shaft in the suprapubic fat pad. Weight loss reveals this hidden length, making the visible penis appear larger.
Jelqing exercises have been scientifically proven to increase penis size.
Answer: FICTION
There are ZERO peer-reviewed clinical studies supporting jelqing for size gains. All evidence is anecdotal from internet forums (with severe survivorship bias). Urologists warn it can cause Peyronie's disease and vascular damage.
Erectile dysfunction is an early warning sign of heart disease.
Answer: FACT
ED symptoms precede cardiovascular events by 3-5 years on average. The penile arteries (1-2mm) are smaller than coronary arteries (3-4mm), so atherosclerosis shows up there first. ED is now considered a cardiovascular risk marker.
Circumcision significantly affects penis size.
Answer: FICTION
Meta-analyses and comparative studies have found no statistically significant difference in erect penile length or girth between circumcised and uncircumcised men.
There is an FDA-cleared implant that can permanently increase penis size.
Answer: FACT
The Penuma silicone sleeve implant is FDA-cleared for cosmetic penile augmentation. Clinical studies show average gains of +2.5-3.8 cm in length and +3.1-3.4 cm in girth, with 82% patient satisfaction.
Men in warmer climates have larger penises on average.
Answer: FICTION
While some early studies suggested a latitude correlation, modern meta-analyses with proper measurement controls have NOT confirmed this. The "Bergmann's rule" adaptation hypothesis for genitalia is not supported by quality data.
Your penis can break even though it has no bones.
Answer: FACT
"Penile fracture" is a rupture of the tunica albuginea, the tough fibrous sheath around the corpora cavernosa. It typically occurs during vigorous intercourse and requires emergency surgery.
Testosterone supplements will make an adult man's penis grow.
Answer: FICTION
After puberty, the penis is no longer responsive to testosterone for growth. The androgen receptors in penile tissue that drive growth are active during fetal development and puberty. In adults, testosterone affects libido and erection quality, not size.
85% of women are satisfied with their partner's penis size.
Answer: FACT
Lever et al. (2006) surveyed 52,031 people and found 85% of women were satisfied with their partner's size, while only 55% of men were satisfied with their own — highlighting a significant perception gap.
Cold water permanently shrinks your penis.
Answer: FICTION
Cold causes temporary vasoconstriction that can reduce flaccid size by 50% or more, but this is completely reversible. The cremaster muscle also contracts, pulling the testes (and penis) closer to the body for warmth.