What is the average size ?

While results vary across studies, the consensus is that the mean human is approximately 12.9–15 cm (5.1–5.9 in) in length with a 95% confidence interval of (10.7 cm, 19.1 cm) (or, equivalently, 4.23 in, 7.53 in).[5][6][7] The typical girth or cirference is approximately 12.3 cm (4.85 in) when fully erect. Yet, one reputable source claims that the relaxed human has an average length of only 4 inches (≈10.2 cm) and diameter of 1¼ inches (≈3.2 cm) while fully erect it has an average length of 6 inches (≈15.2 cm) and diameter of 1½ inches (≈3.8 cm).[8] The mean size is slightly greater than the median size. Studies have not found a relation between size and race