S — Approx. age: 0–1 year · Head circumference: 46–48 cm · Hat height (laid flat): 16.5 cm · Hat width (laid flat): 21.5 cm
M — Approx. age: 1–2 years · Head circumference: 48–50 cm · Hat height (laid flat): 17.5 cm · Hat width (laid flat): 22 cm
L — Approx. age: 2–5 years · Head circumference: 50–52 cm · Hat height (laid flat): 18 cm · Hat width (laid flat): 23 cm
Measurements may vary by approximately 2–3 cm due to manual measurement.