Reformation to Reiss clothing size
The short answer
Reformation M is Reiss 12 by the two brands' own charts.
Both brands publish the body bust each size is cut for, so every row matches a bust, not a letter or a number.
| Reformation | Reformation builds it for | Reiss, by chart | Same label | Reiss builds it for | Reiss also prints |
|---|---|---|---|---|---|
| XS | bust 33 in, waist 25 in, hip 36 in | 8 | not published | bust 33 in, waist 26 in, hip 36 in | US 4 · Letter S · FR 38 · IT 40 · AU 8 · EU (as printed) 36 |
| S | bust 35 in, waist 27 in, hip 38 in | 10 | not published | bust 35 in, waist 28 in, hip 38 in | US 6 · Letter S · FR 40 · IT 42 · AU 10 · EU (as printed) 38 |
| M | bust 37 in, waist 29 in, hip 40 in | 12 | not published | bust 37 in, waist 30 in, hip 40 in | US 8 · Letter M · FR 42 · IT 44 · AU 12 · EU (as printed) 40 |
| L | bust 39.5 in, waist 31.5 in, hip 42.5 in | 14 | not published | bust 39 in, waist 31.5 in, hip 42 in | US 10 · Letter M · FR 44 · IT 46 · AU 14 · EU (as printed) 42 |
| XL | bust 41.5 in, waist 33.5 in, hip 44.5 in | 16 | not published | bust 41 in, waist 33.5 in, hip 44 in | US 12 · Letter L · FR 46 · IT 48 · AU 16 · EU (as printed) 44 |
| 1X | bust 45 in, waist 37.5 in, hip 47.5 in | not made | not published | not published | not published |
| 2X | bust 48 in, waist 40.5 in, hip 50.5 in | not made | not published | not published | not published |
| 3X | bust 51 in, waist 43.5 in, hip 53.5 in | not made | not published | not published | not published |
What wearers say
Charts describe a garment, not a fit. We do not collect fit reports for this category yet, so this table is the two brands' own claims and nothing more.
Sources
- Reformation size guide, read on 2026-09-18. Reformation on TrueToSize
- Reiss size guide, read on 2026-09-18.