The differences in the size of the penis, just like those in height, fatness, leanness, and facial features, are numerous. There are variations in length and thickness. In recent years, mainland China has conducted three surveys on the size of the penis in healthy individuals, with the following results: In Beijing, a sample survey of 1000 people showed an average circumference of 8.22 cm, a length at rest between 4.5-8.6 cm, and an average length of 6.55 cm. In Lanzhou, a survey of 1412 people showed an average circumference of 8.3 cm, a length at rest between 4-14.5 cm, and an average length of 8.38 cm.