True-to-Size Millimeter Sizing Comparison
Franco Sarto Bocca vs Franco Sarto Cason Loafer
Detailed size conversion chart, cavity measurements in millimeters, and crowd-sourced fit advice for choosing your perfect size.
Interactive Size Converter
Select what size you wear in the Bocca to see your calculated size in the Cason Loafer.
Complete Size Conversion Matrix
Direct millimeter-calibrated mapping comparing all available sizes between both shoes.
| Bocca (US) | Internal Cavity | Cason Loafer Equivalent | Match Accuracy | Fit Difference |
|---|---|---|---|---|
| US 4.5 | 233 mm | US 4.5 | 53% | +4.0 mm |
| US 5 | 237 mm | US 4.5 | 100% | 0.0 mm |
| US 5.5 | 240 mm | US 5 | 88% | +1.0 mm |
| US 6 | 243 mm | US 5.5 | 88% | +1.0 mm |
| US 6.5 | 247 mm | US 6 | 100% | 0.0 mm |
| US 7 | 250 mm | US 6.5 | 88% | +1.0 mm |
| US 7.5 | 253 mm | US 7 | 88% | +1.0 mm |
| US 8 | 257 mm | US 7.5 | 100% | 0.0 mm |
| US 8.5 | 260 mm | US 8 | 88% | +1.0 mm |
| US 9 | 267 mm | US 8.5 | 65% | -3.0 mm |
| US 9.5 | 270 mm | US 9 | 88% | +1.0 mm |
| US 10 | 273 mm | US 9.5 | 88% | +1.0 mm |
| US 10.5 | 277 mm | US 10 | 100% | 0.0 mm |
| US 11 | 280 mm | US 10.5 | 88% | +1.0 mm |
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Frequently Asked Questions
How does the Bocca size compare to the Cason Loafer?
The Cason Loafer provides about 4mm more internal length than the Bocca. We suggest ordering 1/2 size down in Cason Loafer. The Bocca has an internal fit offset of 0mm compared to 4mm for the Cason Loafer.
Do these shoes fit wide feet comfortably?
The Bocca has a standard medium width profile, while the Cason Loafer is standard medium.