Sizes for Fitkicks shoes, Kozikicks shoes, and Sidekicks shoes are set by the manufacturer. Here are their published size recommendations:
There are no other sizes of authentic Fitkicks shoes, Kozikicks shoes and Sidekicks shoes, though you may see them listed in other marketplaces with different size equivalents. Those changes are usually made by the retailer and represent their opinions.
CC Sidewalk prefers to list the manufacturer's size recommendations as the standard. But we do offer our own opinions.
The Fit kicks shoe upper is mostly spandex and quite stretchy. However, the toe patch is microfiber and does not stretch much. We recommend one size larger if you are near the top of a size bracket, and definitely the larger size if you are in-between. The shoes are true to size as long as your feet and ankles are pretty much average (aka medium). If your feet are wider, thicker, sensitive to tightness in the toes, or otherwise have a disease process such as diabetes, then choose one size larger. The larger size will not be loose or floppy because the ankle opening is high on the foot.
The Sidekicks shoes are meant to cover a larger size range, and the upper openings are elastic with reasonable stretch. The Energy/Glitter line offers the most stretchable uppers, followed by Original and Animal. The Patent line is pretty stiff and does not stretch much at all. If your feet are wider, thicker, sensitive to tightness in the toes, or otherwise have a disease process such as diabetes, then choose one size larger. The larger size may be a little bit loose.
The Vim and Vigr compression socks are best fitted by calf size. Measuring your calf at the widest point will help achieve a comfortable and healthy fit. Find your calf size range first, and then consider shoe size and your own level of comfort with compression therapeutic apparel.