As a rule of thumb, Freed of London pointe shoes run 2.5 sizes smaller than American street shoes sizes.
Freed Pointe Shoes-to-American Street Shoe Size Conversion Chart

Toe Pads
Also, take into account if you intend to wear toe pads or something similar as these can actually increase shoe length by as much as a half size, or width by an additional size.
Veronese Sizes
Veronese shoe sizes run 16.5 to 17.5 sizes larger than American street shoe sizes. See the one-to-one size conversion chart below:















