What is the average flaccid and erect penis length worldwide?

1. The headline numbers: what the literature reports

A landmark systematic review of measured data commonly cited in summaries found an average erect length of 13.12 cm (5.17 in) and average flaccid length around 9.16 cm, with stretched flaccid length close to erect (13.24 cm), figures reproduced across subsequent compilations and data aggregators ^{[1] [2]}. Other public-facing compilations that combine varied sources give similar ballpark figures — for example, a world-average figure of about 13.59 cm appears in another dataset, reflecting differences in included studies and methods ^[3]. Visualizations and media summaries that aggregate country rankings generally place typical erect averages between roughly 12 and 15 cm, while noting outliers in individual-country reports ^{[5] [6]}.

2. Measurement matters: why reported averages diverge

Reported means differ markedly depending on whether measurements were taken by medical staff or self-reported: self-measurement and online surveys tend to overestimate length (by about 1.3 cm in some corrections), while professionally measured studies produce lower, more consistent averages ^{[2] [1]}. Definitions matter too — “flaccid,” “stretched,” and “erect” lengths are distinct states and are sometimes conflated in public summaries; stretched flaccid length often approximates erect length in clinical settings, but measurement techniques (e.g., pressing the fat pad to the pubic bone) change absolute values ^[1].

3. Geographic and temporal variation: small differences, big headlines

Country-by-country rankings have captured public attention, with datasets placing some nations higher or lower, but many of those rankings rely on mixed-quality sources and small samples and therefore exaggerate differences ^{[3] [5]}. A rigorous meta-analysis found that mean erect length increased over recent decades — about a 24% increase over roughly 29 years after adjustments — suggesting temporal trends that complicate simple cross-sectional “by-country” claims ^{[7] [4]}. Even so, the consensus range across regions still clusters in the low-to-mid teens of centimeters for erect length ^{[4] [3]}.

4. Flaccid versus erect: what each measure tells clinicians and the public

Flaccid measurements are more variable and sensitive to temperature, body composition, and short-term physiologic state, making them poorer predictors of erect length; reviews place average flaccid length at roughly 9–10 cm, while erect length centers near 13 cm ^[1]. Stretched flaccid length is often used in clinical studies as a proxy for erect length because it correlates closely with measured erection length when standardized forces and technique are used, but inconsistent stretching protocols across studies introduce error ^{[1] [6]}.

5. Uncertainties, biases and what the data cannot say

Available datasets synthesize heterogeneous studies with variable sample sizes, inconsistent measurement standards, and different populations, which means any single “global average” is an estimate with important caveats — meta-analyses try to adjust for these biases but cannot eliminate them entirely ^{[3] [2] [4]}. Self-reports reliably inflate averages, country rankings often reflect small or non-representative samples, and some popular compilations pool clinical and self-measured data without transparent weighting, so apparent extremes should be treated skeptically ^{[2] [5]}.

6. Bottom line — an evidence-based summary

Synthesizing peer-reviewed reviews and major aggregated datasets yields a defensible global mean erect length near 13.1 cm (≈5.16–5.2 in) and a flaccid mean generally around 9–10 cm, with stretched flaccid values approximating erect measures in clinically measured cohorts; country-level and self-reported figures vary more widely and are subject to systematic overestimation and sampling error ^{[1] [2] [3] [4]}. These are population averages; individual variation is large and measurement method is the dominant source of reported differences ^[1].