True-to-Size Millimeter Sizing Comparison
Jordan 4Rm vs Jordan Spizike Low
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 4Rm to see your calculated size in the Spizike Low.
Complete Size Conversion Matrix
Direct millimeter-calibrated mapping comparing all available sizes between both shoes.
| 4Rm (US) | Internal Cavity | Spizike Low Equivalent | Match Accuracy | Fit Difference |
|---|---|---|---|---|
| US 5 | 237 mm | US 5 | 99% | +0.1 mm |
| US 5.5 | 240 mm | US 5.5 | 99% | +0.1 mm |
| US 6 | 243 mm | US 6 | 99% | +0.1 mm |
| US 6.5 | 250 mm | US 6.5 | 99% | +0.1 mm |
| US 7 | 253 mm | US 7 | 99% | +0.1 mm |
| US 6 | 257 mm | US 6 | 99% | +0.1 mm |
| US 6.5 | 260 mm | US 6.5 | 99% | +0.1 mm |
| US 7 | 267 mm | US 7 | 99% | +0.1 mm |
| US 7.5 | 270 mm | US 7.5 | 99% | +0.1 mm |
| US 8 | 273 mm | US 8 | 99% | +0.1 mm |
| US 8.5 | 280 mm | US 8.5 | 99% | +0.1 mm |
| US 9 | 283 mm | US 9 | 99% | +0.1 mm |
| US 9.5 | 287 mm | US 9.5 | 99% | +0.1 mm |
| US 10 | 293 mm | US 10 | 99% | +0.1 mm |
| US 10.5 | 297 mm | US 10.5 | 99% | +0.1 mm |
| US 11 | 300 mm | US 11 | 99% | +0.1 mm |
| US 11.5 | 303 mm | US 11.5 | 99% | +0.1 mm |
| US 12 | 307 mm | US 12 | 99% | +0.1 mm |
| US 12.5 | 313 mm | US 12.5 | 99% | +0.1 mm |
| US 13 | 316 mm | US 13 | 99% | +0.1 mm |
| US 14 | 322 mm | US 14 | 99% | +0.1 mm |
| US 15 | 328 mm | US 15 | 99% | +0.1 mm |
| US 16 | 334 mm | US 16 | 99% | +0.1 mm |
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Frequently Asked Questions
How does the 4Rm size compare to the Spizike Low?
Both shoes share a very similar length profile. We recommend ordering your standard size in both. The 4Rm has an internal fit offset of 0.08mm compared to 0.16mm for the Spizike Low.
Do these shoes fit wide feet comfortably?
The 4Rm has a snug/narrow width profile, while the Spizike Low is roomy/wide.