Chacos are well known for their adjustable straps and bright colors. The sandals only come in whole sizes, leading to some confusion for those that typically wear a half size. Typically the advice is, if you wear a half size to go down to the next whole size for Chacos. For many people that simple rule of sizing will get them in the right Chaco size. However sizing Chacos is much more than just going down to a whole size. Chacos are sized by the heel-to-ball measurement instead of overall foot length like most shoes.