US 2 (0-6 Months, 3.75" Sole).
US 3 (3-6 Months; 4.125" Sole)
US 4 (6-12 Months, 4.5" Sole).
US 5.5 (12-18 Months, 5.0" Sole).
US 6.5 (18-24 Months, 5.25" Sole).
US 8 (2-3 Years, 5.75" Sole).
US 9.5 (3-4 Years, 6.25" Sole).