What is a normal penis length?

For any man who's secretly wondering if he measures up, here's the answer: British researchers set out to determine what can be considered a "normal" penis length by analyzing prior studies and identifying 20 that met their criteria. That gave them a data pool of 15,521 males ages 17 to 91 with which to conduct the first "formal systematic [review] of penile size measurements." Using the men's measurements, they created nomograms, or graphical diagrams that plot the relationship between two variables (in this case, length and percentile), of flaccid and erect penile size measurements. Their conclusion: The average length of a flaccid penis is 3.6 inches, and the average length of an erect penis is 5.16 inches. They also determined average girth: 3.7 inches when flaccid, and 4.6 inches when erect. The average stretched flaccid length was 5.21 inches. Dr. David Veale explains that the nomograms should "help doctors reassure the large majority of men that the size of their penis is in the normal range," as it easily illustrates whether a man who isn't exactly average falls in the 40th percentile, for instance, or the 65th. As for those at the extremes, the pool is small: Just 2.28% of males' members would be considered "abnormally small"; roughly the same percentage have an abnormally large penis. What the researchers didn't find: any differences in penile size across different races or any correlation between the length of a man's foot and his penis.