True-to-Size Millimeter Sizing Comparison
Rocket Dog Jazzin vs Rocket Dog Rainbow
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 Jazzin to see your calculated size in the Rainbow.
Complete Size Conversion Matrix
Direct millimeter-calibrated mapping comparing all available sizes between both shoes.
| Jazzin (US) | Internal Cavity | Rainbow Equivalent | Match Accuracy | Fit Difference |
|---|---|---|---|---|
| US 3.5 | 244 mm | US 4 | 93% | -0.6 mm |
| US 4 | 247 mm | US 4.5 | 95% | +0.4 mm |
| US 4.5 | 251 mm | US 5 | 93% | -0.6 mm |
| US 5 | 254 mm | US 5.5 | 93% | -0.6 mm |
| US 5.5 | 257 mm | US 6 | 95% | +0.4 mm |
| US 6 | 261 mm | US 6.5 | 93% | -0.6 mm |
| US 6.5 | 264 mm | US 7 | 60% | +3.4 mm |
| US 7 | 271 mm | US 7.5 | 93% | -0.6 mm |
| US 7.5 | 274 mm | US 8 | 93% | -0.6 mm |
| US 8 | 277 mm | US 8.5 | 95% | +0.4 mm |
| US 8.5 | 281 mm | US 9 | 93% | -0.6 mm |
| US 9 | 284 mm | US 9.5 | 93% | -0.6 mm |
| US 9.5 | 287 mm | US 10 | 95% | +0.4 mm |
| US 10 | 291 mm | US 10.5 | 93% | -0.6 mm |
| US 10.5 | 294 mm | US 11 | 93% | -0.6 mm |
| US 11 | 297 mm | US 11.5 | 95% | +0.4 mm |
| US 11.5 | 301 mm | US 12 | 93% | -0.6 mm |
| US 12 | 304 mm | US 12.5 | 93% | -0.6 mm |
| US 12.5 | 307 mm | US 13 | 95% | +0.4 mm |
| US 13 | 311 mm | US 14 | 72% | +2.4 mm |
| US 14 | 317 mm | US 14 | 57% | -3.6 mm |
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Frequently Asked Questions
How does the Jazzin size compare to the Rainbow?
The Rainbow is about 4mm shorter than the Jazzin. We suggest ordering 1/2 size up in Rainbow. The Jazzin has an internal fit offset of 3.68mm compared to 0.08mm for the Rainbow.
Do these shoes fit wide feet comfortably?
The Jazzin has a roomy/wide width profile, while the Rainbow is roomy/wide.