The cms measurement shown is the insole length of shoe.  Have your child stand on a ruler or tape measure to get their most accurate foot measurement.  It is recommended to go a ballet shoe that is no more than 0.5cm bigger than foot measurement as they are meant to be a fitted shoe & will trip over the toe if there is too much room at the end.

Once you have placed your order, please get in touch with Miss Sarah to confirm your size.