What are the typical average and percentile values for erect and flaccid penis length and girth?

1. What the large studies say: consensus figures and how they were measured

Systematic reviews and large datasets published in urology journals and summarized by news outlets and health sites converge on a tight range: an average erect length near 13.1 cm (≈5.16 in) and average erect circumference about 11.66 cm (≈4.59 in), with flaccid length roughly 9.16 cm (≈3.6 in) and flaccid girth about 9.31 cm (≈3.66 in) ^{[2] [1]}. These figures come from studies that pooled many subjects and—crucially—often used standardized, clinician-measured protocols (length measured from pubic bone to glans tip, girth at mid-shaft or base), which tends to give lower averages than self-reported surveys ^{[3] [1]}.

2. Percentiles: how rare are very small or very large sizes?

The pooled distributions are fairly narrow: an erect 10 cm (≈3.9 in) falls near the 5th percentile, meaning about 5% of men are at or below that length; an erect 16 cm (≈6.3 in) lies near the 95th percentile, so only about 5% are larger ^[2]. One large review reported the 50th-percentile (median) erect length ~13.1 cm and circumference ~11.6 cm, with 25th/75th percentiles roughly one centimeter below and above the median, illustrating most men cluster within a few centimeters of the mean ^[1].

3. Why reported numbers vary: measurement method and bias

Differences between studies largely reflect measurement method and sampling. Clinician-measured studies (where an examiner measures from pubic bone to tip) yield lower and more consistent averages; internet/self-measured surveys typically overestimate length by a noticeable margin ^{[3] [4]}. Some datasets adjust self-reports downward; websites aggregating by country or self-reporting often show wider variation and higher means ^{[4] [5]}. Meta-analyses note heterogeneity and urge standardized measurement to reduce bias ^[6].

4. Girth matters in the data—and to partners, but opinions differ

Girth (circumference) is reported with similar consistency: pooled averages center around 11.66 cm erect and about 9.3 cm flaccid ^{[2] [1]}. Some behavioral studies cited in reviews suggest many partners prioritize girth over length, but satisfaction is complex and not solely determined by size; the clinical literature emphasizes functionality and perception rather than fixed “ideal” dimensions ^[1].

5. Clinical thresholds and definitions (micropenis and percentiles)

Clinically, definitions for abnormally small measurements depend on percentiles within a given reference population. One prospective study defined micropenis relative to the 5th percentile—e.g., flaccid length ≤7 cm or stretched length ≤10 cm in that sample—illustrating clinicians use population percentiles to set thresholds rather than a single universal cut-off ^[7]. Large reviews similarly use percentile framing to contextualize extreme values ^[2].

6. Limitations, open questions and how to read country rankings

Important caveats: pooled means mask within-population variability, study methods differ, and many country-by-country rankings mix clinician measurements with self-reports, producing questionable comparisons ^{[4] [3]}. Systematic reviews call out measurement heterogeneity as a major limitation and recommend standardized protocols for future work ^[6]. Available sources do not mention any definitive biological links between penis size and fertility in routine clinical terms ^[5].

7. Practical takeaways and where people commonly misread data

Most men fall near the reported averages and percentiles: if your erect length is around 13 cm and girth near 11–12 cm, you are near the global median; values under ~10 cm erect are uncommon but not unheard of and sit near the lower 5th percentile, while lengths >16 cm are uncommon and sit near the 95th percentile ^{[1] [2]}. Beware popular claims of very large “averages” (e.g., 7 in) that rely on self-selected or unadjusted self-reports—those are contradicted by clinician-measured pooled analyses ^{[2] [3]}.

If you want exact percentile placement for a specific measurement, online calculators exist that apply these pooled distributions, but their inputs and assumptions vary—choose ones that cite clinician-measured meta-analytic sources if you want estimates grounded in the literature ^{[8] [9]}.