If you have purchased Archetypes, try .5 size larger.
(Size 9 Archetypes = Size 9.5 Soleils)
Our size chart was made for the Archetypes, and we did our best to match the sizing for the new shoes to that.
The Soleil and the Canvas Highs were built on equipment with identical length and width specs as the Archetypes, but the Soleils feel slightly shorter.
If you have not purchased Archetypes, which fit most people "true-to-size", your best bet is +.5 sizes from your typical size.
If you are usually a 10, start with 10.5.
We think this discrepancy is from a supportive material in the toe cap used for structuring that part of the shoe. Within a couple of wears, these materials soften and it fits like a glove, and you may prefer that fit over exchanging for a half size larger.
Exchanges are covered with our $3.98 package protection at checkout, so use that to swap for the right size (tried-on shoes must be in "New" condition so we can repackage and resell them- we are a small company!)