Average erect length measures 13.12 cm and erect girth 11.66 cm per professional studies. Self-reported lengths exceed professional measurements by significant margins. Flaccid length averages 9.16 cm and does not predict erect size accurately. No correlation exists between penis size and height, weight, BMI, shoe size, or hand size. Weak correlation links longer ring finger to longer penis. Nose size correlates with stretched penile length in Japanese cadavers. Human penis is thickest among primates relative to body size. Myths of oversized black penises lack scientific support. No evidence shows penis size differences between races or ethnicities. Gay men self-report slightly larger penises than straight men per Kinsey data. Women prefer girth over length and average sizes for satisfaction. Preferred penis for long-term partners is 16 cm long and 12.2 cm girth. Larger penis circumference increases condom breakage risk. Testosterone drives penis growth during puberty but not after. Environmental chemicals like phthalates reduce penis size in newborns. Micropenis affects 0.6% of men due to genetic or hormonal deficiencies. Shrinkage occurs from cold, anxiety, or Peyronie's disease. Porn exaggerates penis sizes fueling inaccurate perceptions. Men overestimate average size and worry excessively about their own.