Can foot length or shoe size reliably predict erect penile length?
Executive summary
Major peer‑reviewed studies and reviews find at best a very weak statistical relationship between foot/height and penile length and conclude foot size (or shoe size) is not a reliable predictor of erect or stretched penile length (see clinical studies of 63, 104, and 800 men) [1] [2] [3]. Some isolated correlations appear in older, small studies (weak r ≈ 0.26–0.27), but authors explicitly state those correlations are too weak to serve as practical estimators [1] [4].
1. The headline: “Big feet = big penis?” — what the data actually show
Multiple empirical studies directly measuring men’s feet and penile dimensions find either no statistically significant link (the 104‑man prospective study) or at most a very weak correlation that is not useful for prediction (the 63‑man Canadian study and others reporting r ≈ 0.26–0.27) [2] [1] [4]. Larger, more recent series also report low or no correlation between foot length and penile measures when measured by clinicians rather than self‑report [3].
2. Why a weak correlation doesn’t make a useful predictor
A statistically significant correlation (a non‑zero r) can exist without having practical predictive value. The studies that reported a relationship described it as weak and explicitly concluded that height or foot size “would not serve as practical estimators of penis length” [1]. The 2002 St Mary’s/University College London study measuring 104 men found no statistically significant correlation between shoe size and stretched penile length [2] [5].
3. Measurement methods matter — and many early claims relied on self‑report
Studies that measure participants directly (clinician‑measured stretched or erect length and measured foot size) are considered more reliable than surveys that ask men to self‑report. The 104‑subject study removed self‑report bias by having examiners measure both shoe size and stretched penile length and found no link [2]. Reviews and larger prospective series echo that clinician measurement finds low or no correlation [3].
4. Larger, multi‑center data reinforce the “not predictive” conclusion
A prospective study of 800 men recorded left foot length and multiple penile measurements and reported low or no correlation between foot length and flaccid or stretched penile length, with the exception that flaccid and stretched lengths correlated with each other; the authors did not endorse foot size as a practical estimator [3]. This larger sample strengthens the view that any earlier hints of association do not generalize.
5. Where the weak associations come from — biology and statistics
Some studies found small but statistically significant associations between overall body size (height, foot length) and penile measures — essentially reflecting that larger people tend to have proportionally larger body parts — but correlation coefficients were low (r ≈ 0.26–0.27), meaning most individual variation is unexplained by foot size or height [1] [4]. That low r yields wide prediction intervals, so you cannot reliably infer an individual’s erect length from shoe size.
6. Alternative anthropometric predictors and conflicting findings
Some work has explored other anthropometric markers (digit ratio, anogenital distance, nose size in cadaver studies) as correlates; for example, one multivariate analysis found anogenital distance to be a stronger independent predictor of stretched penile length than foot size (β = 0.618, p < 0.001) in that dataset [6]. Wikipedia’s summary also notes digit ratio findings and that flaccid/stretch measures do not always predict erect length reliably [7]. Different studies disagree on which minor predictors hold up, underscoring that no simple external measure is a robust, clinical predictor.
7. Popular reporting vs. clinical summaries — myth persists
Popular outlets and fact‑checkers (Snopes, NHS coverage summarized in news pieces) have repeatedly debunked the “shoe size predicts penis size” myth by citing the clinical studies that found no relationship or only negligible links [8] [9]. Media headlines sometimes overemphasize small statistical findings or novel correlations (e.g., nose size in a cadaver series) without conveying the limited predictive power reported by researchers [10] [7].
8. Bottom line for readers
Available clinical evidence does not support using foot length or shoe size to predict an individual’s erect penile length; researchers and reviewers explicitly call such an approach impractical or unsupported [2] [1] [3]. If you are looking for reliable predictors, current studies suggest other measures (e.g., anogenital distance in that particular analysis) may correlate more strongly, but no universally accepted external surrogate for erect penile length exists in the cited literature [6] [3].
Limitations: available sources focus on measured stretched or flaccid length and on clinician‑measured anthropometrics in specific samples; they do not establish a universally applicable predictive rule for erect length and do not uniformly sample all populations [2] [3].