Infant/Child

	Preemie	Baby	Toddler	Child	Tween
Circumference (in.)	9–12	14–16	16–18	18–20	20–22
(cm.)	23–30.5	35.5–40.5	40.5–46	45.5–51	51–56

Adult

	Woman	Man
Circumference (in.)	21–23	22–24
(cm.)	53–58.5	56–61