Different types of shoes have slightly different sizing. It is best to check the sizing of each model in the shoe's description where we measured every inside  of every model.

Here is a sizing of wide barefoot sneakers. They run almost one size bigger than non barefoot sandals. Below you can find toddlers sandals with arch support.

Orthopedic sandals for older children, sizes EU 27 - 37:

Arch supporting sandals for older children, EU 27 - 36:

Women and unisex orthopedic sandals: