Surefit Size Chart [Baby] This chart applies to the following Surefit styles: Kyra and Khloe. Get the perfect fit every time. 1. Measure your child’s foot length 2. Add 10 mm growth room [keep in mind for babies, closer to 5mm growth room is ok as they are not walking] 3. Match that to the inner length of the size you need Surefit Size [Baby] Our Aus Size Inner shoe measurement [mm] 18 3 115 19 3.5 120 20 4 125 21 4.5 132 22 5.5 140 Surefit sizing can vary between different styles, so please use the right size chart for the style you are falling in love with and about to purchase. To make this easy, the styles are listed at the top of each of our Surefit size charts.