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Measurement bias in penis size studies

The limitations of current research on penis size due to measurement bias, self-reporting, and mixing of geography and ethnicity.

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Jan 19, 2026
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6.5 inch penis

A 6.5‑inch erect penis sits at the high end of published ranges: many reviews put average erect length at roughly 5.1–5.5 inches, and large reviews find that about 95% of men fall between roughly 3.9 ...

Jan 16, 2026

How accurate are self-reported penis size surveys compared to clinical measurements?

Self-reported penis size surveys are systematically less reliable than clinician-measured data: most studies find self-reports skew larger, driven by social desirability, measurement differences and s...