This Owl Hat is super cute, made with the softest acrylic/cotton yarn and is very soft on the skin. All sizes Preemie to Adult are available. To measure the head, use a flexible measuring tape, measure the circumference at the widest part of your head, just above the eyebrows. If you are unable to measure the person you are purchasing for, here is a helpful measurement chart so that you know what size to order: Preemie 10"- 12" Newborn 12”- 14” 0 to 3 Months 13" - 1 3 to 6 Months 14”- 16” 6 to 12 Months 16”- 18” 12 Months to 2 Years 18”- 20” 3 Years to 10 years 20”- 21” Teen to Adult 20”- 22”