Tanner Stages of Puberty: Complete Guide for Boys and Girls

Tanner Stages (Sexual Maturity Ratings) classify pubertal development (1–5).

Boys: Genital and Pubic Hair Development

• Stage 1: Prepubertal. Testes <2.5cm, scrotum prepubertal.
• Stage 2: Testes 2.5–3.2cm, scrotum thins/reddens. Sparse pubic hair.
• Stage 3: Testes 3.3–4.0cm, penis lengthens. Pubic hair darker, coarser, spreading.
• Stage 4: Testes 4.1–4.5cm, penis widens. Pubic hair adult-type, not yet thighs.
• Stage 5: Testes >4.5cm, adult genitalia. Pubic hair to medial thighs.

Girls: Breast and Pubic Hair Development

• Stage 1: Prepubertal. Flat chest, no pubic hair.
• Stage 2: Breast buds, areolae enlarge. Sparse pubic hair.
• Stage 3: Breast/areola enlarge further. Pubic hair darker, coarser.
• Stage 4: Areola forms secondary mound. Pubic hair adult-type, not thighs.
• Stage 5: Adult breast contour (areola recess). Pubic hair to medial thighs.

Sequence of Events

Girls: Thelarche → Pubarche → Menarche → Axillary hair → Adult shape.
Boys: Gonadarche (testicular enlargement) → Pubarche → Penile growth → Voice deepening → Facial hair.

Timing varies widely; onset 8–13 years (girls), 9–14 years (boys).