1 = 3 month – 9 month (head circumference 40 - 45cm)

2 = 12 month - 18 month (head circumference 43 - 48cm)

3 = 2 - 5 years (head circumference 46 - 52cm)

4 = 6 - 10 years (head circumference 50 - 56cm)

1 = 3 mth – 18 mth

3 = 2 – 10 years

3 = 2 - 5 years (head circumference 46 - 52cm)

4 = 6 - 10 years (head circumference 50 - 56cm)

1 = 3 mth- 18mth (without thumb)

3 = 2 - 5 years (with thumb)

 4 = 6 - 10 years (with thumb)

1 = 3 mth – 18 mth

2 = 2 - 10 years