Should be start from P.12. There also have the charts on Head Circumference, Weight, Length (0-2years & 2-18 years). If you want to check what size your BB is, you can weigth your BB and check which area your BB. For example, the BB boy is now 2 months and he is now 5.5kg, then he reach the line 50. That means he is the medium size BB.