Methodology
Sizetab compares shoe size chart rows and uses CM as a cross-brand baseline only where the selected charts provide a comparable CM value. EU, US and UK labels are then shown in context.
How sizes are mapped
On public brand-comparison pages, Sizetab compares rows by CM when both selected charts provide a usable CM value. A target row is valid only inside the target chart range; values outside that range have no direct equivalent.
If a public comparison row does not have a usable CM baseline, it is omitted from that CM comparison. Other conversion paths may use controlled fallback logic, but a fallback must be labeled and must not be presented as equivalent to a CM match.
How systems are treated
CM is used as a numeric length baseline where the source charts define it comparably. Its meaning can vary between foot length, JP/CM conventions or derived values, so chart provenance and data notes matter. EU, US and UK labels remain brand- and gender-dependent.
Official vs approximate
Source and data-type labels are shown only when they have been reviewed and stored for the relevant chart. Copied, approximate or transformed data is described by its actual provenance rather than being promoted to “official” by inference.
Known limitations
Charts do not capture width, last shape, padding, materials, socks or personal preference. Model-specific notes can override a clean chart match, especially in running, skate and basketball shoes.