Wrong size is the fastest way to lose trust in adaptive footwear. The goal is not “as small as possible”. The goal is a stable heel, space for the brace or a growing foot, and a width that does not pinch.
Start with the measurement you already have
Use a recent foot length in centimetres, or the last pair that actually worked. Convert carefully: our product pages show EU size with the US equivalent underneath. If you are between sizes, tell us whether the shoe is for an AFO, swelling, or a wide forefoot — the answer is not always “go bigger”.
Width is not optional
Many BILLY kids styles come in wide (W) and extra-wide (XW). An AFO often needs the extra volume more than an extra EU size. Trying to solve width by sizing up can leave the heel slipping.
Insoles and orthotics
Removable insoles let you drop in a custom orthotic or reclaim depth for a brace. If the clinic issued a foot orthosis, take the original insole out first, then test the fit. Orthopaedic styles such as Princepard are built for structured support and healthy development — still confirm the size against a measured foot, not the child’s age.
Pre-order and in-stock sizes
Some sizes ship later. A faded, struck-through size on our product pages means that size is offered as a pre-order, not that it is unusable. Delivery is typically a few weeks. In-stock sizes stay fully visible.
When in doubt, send a photo of the AFO and the current shoe size on WhatsApp. FARID HUB is a consultative shop: we would rather get the pair right than rush a guess.