Converse US 9 corresponds to a 275 mm foot length, which is Korean size 275, EU 42.5 and UK 9.
Runs half a size to a full size large — most people size down half a size.
Chuck Taylors are famous for running large: the same US 9 that is 270 mm elsewhere is closer to 275 mm here. The toe box is narrow, though, so wide feet cannot always take the half size down — worth trying in person.
Converse Full size chart
| US | UK | EU | mm (foot length) | KR (Korea) |
|---|---|---|---|---|
| 6 | 6 | 38.5 | 245mm | 245 |
| 6.5 | 6.5 | 39 | 250mm | 250 |
| 7 | 7 | 40 | 255mm | 255 |
| 7.5 | 7.5 | 40.5 | 260mm | 260 |
| 8 | 8 | 41 | 265mm | 265 |
| 8.5 | 8.5 | 42 | 270mm | 270 |
| 9 | 9 | 42.5 | 275mm | 275 |
| 9.5 | 9.5 | 43 | 280mm | 280 |
| 10 | 10 | 44 | 285mm | 285 |
| 10.5 | 10.5 | 44.5 | 290mm | 290 |
| 11 | 11 | 45 | 295mm | 295 |
| 11.5 | 11.5 | 45.5 | 300mm | 300 |
| 12 | 12 | 46 | 305mm | 305 |
How it fits
How to measure your foot
Stand with your heel against a wall on a sheet of paper and mark the tip of your longest toe. Wall to mark is your foot length in millimetres. Measure in the evening — feet swell slightly through the day, and that is the size you actually wear.
Most people have two slightly different feet, so measure both and use the longer one. Trainers are normally chosen 5-10 mm longer than the foot itself.