Reformation to Gap clothing size
The short answer
Reformation XS is Gap 2 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.
On 3 sizes the charts land two or more sizes from the same label. Brands do not measure the body the same way, so on those rows treat the chart answer and the same label as the two ends of a range.
| Reformation | Reformation builds it for | Gap, by chart | Same label | Gap builds it for | Gap also prints |
|---|---|---|---|---|---|
| XS | bust 33 in, waist 25 in, hip 36 in | 2 | 000 | bust 33.3 in, waist 26.5 in, hip 36.3 in | Letter XS |
| S | bust 35 in, waist 27 in, hip 38 in | 6 | not published | bust 35.3 in, waist 28.5 in, hip 38.3 in | Letter S |
| M | bust 37 in, waist 29 in, hip 40 in | 10 | not published | bust 37.3 in, waist 30.5 in, hip 40.3 in | Letter M |
| L | bust 39.5 in, waist 31.5 in, hip 42.5 in | 12 or 14 | 10 | bust 38.8 in, waist 32 in, hip 41.8 in | Letter L |
| XL | bust 41.5 in, waist 33.5 in, hip 44.5 in | 16 | 12 | bust 42 in, waist 35.5 in, hip 45.3 in | Letter XL |
| 1X | bust 45 in, waist 37.5 in, hip 47.5 in | 20 or 18 | 14 | bust 45.8 in, waist 39.5 in, hip 49.3 in | Letter XXL |
| 2X | bust 48 in, waist 40.5 in, hip 50.5 in | 22 | not published | bust 47.8 in, waist 41.5 in, hip 51.3 in | Letter XXL |
| 3X | bust 51 in, waist 43.5 in, hip 53.5 in | not made | 20 | 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
- Gap size guide, read on 2026-09-18. Gap on TrueToSize