Pedemy All toolsTap the sex, the Tanner stages you see and the age. The tool tells you whether puberty is early, late or on time, and what to do next.
This tool turns a Tanner exam into a decision. Tap the child’s sex, the breast stage (girls) or genital stage with testicular volume (boys), and the pubic hair stage, each described in plain words from Marshall and Tanner’s five stages. In boys, a testicular volume of 4 mL or more on a Prader orchidometer marks the start of central puberty. Enter the age and the tool flags early, delayed or on-time puberty, with first-line tests and red flags.
Precocious puberty is breast development before 8 years in girls or testicular enlargement before 9 years in boys. Following the 2026 Endocrine Society guideline, girls with breast budding between 7 and 8 years can often be watched every 4–6 months. Stage B3 or higher, a growth spurt over 6 cm a year or neurologic signs mean testing now: bone age, morning LH on an ultrasensitive assay (about 0.3 IU/L or more suggests central puberty), FSH, estradiol or testosterone, and thyroid tests. Pubic hair alone before 8 or 9 years is usually benign premature adrenarche, but needs DHEA-S and 17-hydroxyprogesterone.
Delayed puberty is no breast development by 13 years in girls or testes under 4 mL at 14 years in boys (Palmert and Dunkel, 2012). Girls also need evaluation with no period by 15 years or more than 3 years after breast budding. The tool lists the workup: growth chart and bone age, LH and FSH, thyroid tests and prolactin, screening for chronic disease such as celiac disease, and a karyotype when gonadotropins are high or a girl is short (Turner syndrome). A table gives typical US ages for thelarche, testicular growth, peak height velocity and menarche.
Breast development before 8 years in girls, or testicular enlargement to 4 mL or more before 9 years in boys. In girls with breast budding at 7–8 years and no red flags, the 2026 Endocrine Society guideline suggests re-examining every 4–6 months rather than testing straight away.
No breast development by 13 years in girls, or testes still under 4 mL at 14 years in boys. In girls, no period by 15 years or more than 3 years after breast budding also needs evaluation. Constitutional delay is the most common cause, but it is a diagnosis of exclusion.
A volume of 4 mL or more on a Prader orchidometer, or a long axis of about 2.5 cm or more, marks gonadarche, the start of central puberty in boys. In US boys this happens at a mean age of about 11.3–11.8 years.
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