Children's size chart - size 92/98 to 164/170:

For a good fit you need your body measurements.

Size 92/98 104/110 116/122 128/134 140/146 152/158 164/170
Body measurements (in cm)
A Chest circumference 54-55 56-57 58-61 64-67 70-73 76-79 82-85
B Waist circumference 51-52 53-54 55-56.5 58-59.5 61-62.5 64.5-66.5 68.5-70.5
C Hip circumference 55-57 59-61 63-66 69-72 75-78.5 82-85.5 89-92.5
To get the exact body measurements, it is easiest if you have some help from a friend. The measurements are taken directly on the body - in underwear only.