Reformation to Gap jeans size
The short answer
Reformation 30 is Gap 12 by the two brands' own charts.
Both brands publish the body waist each size is cut for, so every row matches a waist, not a tag.
| Reformation | Reformation builds it for | Gap, by chart | Same label | Gap builds it for | Gap also prints |
|---|---|---|---|---|---|
| 23 | waist 23.5 in, hip 34 in | not made | not published | not published | not published |
| 24 | waist 24.5 in, hip 35 in | 00 | not published | waist 24.8 in, hip 34.3 in | Letter XXS |
| 25 | waist 25.5 in, hip 36 in | 0 | not published | waist 25.5 in, hip 35.3 in | Letter XS |
| 26 | waist 26.5 in, hip 37 in | 2 | not published | waist 26.5 in, hip 36.3 in | Letter XS |
| 27 | waist 27.5 in, hip 38 in | 4 | not published | waist 27.5 in, hip 37.3 in | Letter S |
| 28 | waist 28.5 in, hip 39 in | 6 | not published | waist 28.5 in, hip 38.3 in | Letter S |
| 29 | waist 30 in, hip 40.5 in | 8 or 10 | not published | waist 29.5 in, hip 39.3 in | Letter M |
| 30 | waist 31.5 in, hip 42 in | 12 | not published | waist 32 in, hip 41.8 in | Letter L |
| 31 | waist 33.3 in, hip 43.8 in | 14 | not published | waist 33.5 in, hip 43.3 in | Letter L |
| 32 | waist 38.5 in, hip 49 in | 18 or 20 | not published | waist 37.5 in, hip 47.3 in | Letter XL |
| 33 | waist 39 in, hip 50 in | 20 | not published | waist 39.5 in, hip 49.3 in | Letter XXL |
| 34 | waist 40 in, hip 51 in | 20 | not published | waist 39.5 in, hip 49.3 in | Letter XXL |
| 35 | waist 41 in, hip 52 in | 22 | not published | waist 41.5 in, hip 51.3 in | Letter XXL |
| 36 | waist 42 in, hip 53 in | 22 | not published | waist 41.5 in, hip 51.3 in | Letter XXL |
| 38 | waist 44 in, hip 55 in | not made | not published | not published | not published |
What wearers say
Charts describe a garment. People who own both brands describe a fit, and their answer ranks above this table once five of them stand behind it. Pick your size in the converter to see whether there are enough yet.
Sources
- Reformation size guide, read on 2026-09-18. Reformation on TrueToSize
- Gap size guide, read on 2026-09-17. Gap on TrueToSize