No, there is no meaningful correlation between foot size and penile length. This is one of the most persistent myths about male anatomy, but multiple studies have tested it directly and found no statistically significant relationship. A man with size 13 shoes is no more likely to have a larger penis than a man with size 8 shoes.
What the Research Actually Found
The most direct test of this question came from a 2002 study published in BJU International, in which two urologists measured the stretched penile length of 104 men and compared it to their shoe size. The result was unambiguous: there was no statistically significant correlation between the two measurements. The authors concluded that “the supposed association of penile length and shoe size has no scientific basis.”
A larger systematic review that pooled data from up to 15,521 men confirmed this picture. While that analysis did find a consistent correlation between penile length and overall height, the relationship was modest, with correlation values ranging from 0.2 to 0.6. Foot size, which loosely tracks with height, doesn’t independently predict anything about genital dimensions once you account for the general reality that taller people tend to have slightly larger measurements of almost everything.
Why the Myth Feels Believable
There’s a grain of biological logic buried in this belief, which is part of why it persists. During embryonic development, the same family of genes (known as Hox genes, specifically HOXA13) plays a role in shaping both limbs and genitalia. Rare genetic mutations affecting these genes can cause abnormalities in both hands or feet and the urogenital tract simultaneously. So at a deep genetic level, limb development and genital development do share some molecular machinery.
But sharing a genetic toolkit doesn’t mean the two body parts end up proportional to each other. Dozens of other genes, hormones, and growth factors influence how large each structure ultimately becomes. The connection at the embryonic level is real but far too indirect to produce a reliable size-to-size relationship in adults. It’s a bit like noting that the same construction company built two different buildings: the fact that they share a builder tells you nothing about which one is taller.
What Does Correlate With Penile Length
If foot size doesn’t predict anything, what does? The short answer is that no external body measurement is a reliable predictor, but height comes the closest. The systematic review of over 15,000 men found that height had the strongest and most consistent correlation with both flaccid stretched and erect penile length. Even so, the correlation values topped out around 0.6, which in statistical terms means height explains only a fraction of the variation between individuals. You couldn’t look at two men of different heights and confidently guess who has a longer penis.
A study of over 1,000 boys also found significant correlations between penile length and both weight and height during early childhood (r = 0.881 and r = 0.864, respectively), but those numbers reflect the fact that in growing children, nearly every body measurement correlates with every other one. As adults, those tight correlations loosen considerably. Body mass index in particular becomes a poor predictor, partly because excess fat in the pubic area can obscure measurable length without changing the actual organ size.
How Penile Length Is Measured in Studies
One reason casual observations are unreliable is that penile length is surprisingly tricky to measure consistently. The standard clinical approach involves stretching the flaccid penis to its maximum capacity at a 90-degree angle from the body, then measuring along the top surface from the pubic skin to the tip. This “stretched flaccid length” closely approximates erect length and is far more reproducible than measuring a flaccid, unstretched penis, which varies with temperature, arousal, and blood flow.
Even among researchers, technique matters. Studies comparing different measurement approaches have found that pressing the ruler to the pubic bone (rather than starting at the skin surface) gives more accurate and reliable results, especially in overweight men where a fat pad can add a centimeter or more of discrepancy. This means that self-reported measurements, which most men take casually and without standardized technique, are inherently inconsistent and tend to skew optimistic.
Why External Predictors Fall Short
Penile size is determined largely by hormone exposure during fetal development and puberty, along with individual genetic variation that doesn’t map neatly onto other visible traits. Testosterone levels during key developmental windows influence genital growth, but those hormone levels don’t simultaneously dictate foot size, hand span, or nose length in any proportional way. The traits develop on different timelines, respond to different signals, and are shaped by different combinations of the thousands of genes that vary between individuals.
This is why every external “predictor” that folklore has proposed, from shoe size to hand size to the ratio between index and ring fingers, has either failed outright in controlled studies or shown correlations too weak to be useful. The belief that you can read one body part from another is intuitive but wrong. Human bodies simply aren’t scaled-up or scaled-down versions of a single template. They’re assembled from parts that develop semi-independently, which is exactly what the research consistently shows.