The Tanner scale, developed by British pediatrician James Tanner, provides a rating system for the physical development in children and adolescents.

The scale defines physical development based on external primary and secondary sex characteristics. The table below lists the characteristics typical of each stage, such as the size of the breasts, genitals, testicular volume and development of pubic hair.

The typical age listed is a guide only. The tanner stages do not match with chronological age, but rather maturity stages, and that is the main use of these.

Male Stages

description pubic hair typical age (years)
tanner stage 1STAGE 1: testicular volume less than 1.5 ml; small penis of 3 cm or less (prepubertal) no pubic hair at all nine and younger
tanner stage 2STAGE 2: testicular volume between 1.6 and 6 ml; skin on scrotum thins, reddens and enlarges; penis length unchanged Small amount of long, slightly pigmented, downy hair, along the base of the scrotum. 9–11
tanner stage 3STAGE 3: testicular volume between 6 and 12 ml; scrotum enlarges further; penis begins to lengthen to about 6 cm Moderate amount of more curly, pigmented, and coarser hair; more lateral extension. 11–12.5
tanner stage 4STAGE 4: testicular volume between 12 and 20 ml; scrotum enlarges further and darkens; penis increases in length to 10 cm Resembles adult hair in coarseness and curliness, but does not extend to the medial surfaces of the thighs. 12.5–14
tanner stage 5STAGE 5: testicular volume greater than 20 ml; adult scrotum and penis of 15 cm in length Adult pattern. 14+

Female Stages

Stages pubic hair typical age (years)
tanner stage 1STAGE 1: no glandular tissue: areola follows the skin contours of the chest (prepubertal) no pubic hair at all 10 and younger
tanner stage 2STAGE 2: breast bud forms, with small area of surrounding glandular tissue; areola begins to widen Small amount of long, slightly pigmented, downy hair. 10–11.5
tanner stage 3STAGE 3: breast begins to become more elevated, and extends beyond the borders of the areola, which continues to widen but remains in contour with surrounding breast Moderate amounts of more curly, pigmented hair: more lateral. 11.5–13
tanner stage 4STAGE 4: increased breast size and elevation; areola and papilla form a secondary mound projecting from the contour of the surrounding breast Resembles adult public hair in coarseness and curliness, but does not extend to the medial surfaces of the thighs. 13–15
tanner stage 5STAGE 5: breast reaches final adult size; areola returns to contour of the surrounding breast, with a projecting central papilla Adult pattern. 15+

all Tanner Stage images adapted from those by Michał Komorniczak (Poland) (Creative Commons Attribution-Share Alike 3.0 license)

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