Gymshark to MUJI size
The short answer
Gymshark XS is MUJI M by the two brands' own charts. 5 of 6 Gymshark sizes land on a different label at MUJI.
Both brands publish the body chest each size is cut for, so every row matches a chest, not a letter.
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.
| Gymshark | Gymshark builds it for | MUJI Japan sizing, by chart | Same label | MUJI builds it for | MUJI also prints |
|---|---|---|---|---|---|
| XS | chest 37 in, waist 29.5 in | M | XS | chest 34.7 to 37.8 in, waist 29.9 to 33.1 in, hip 35.4 to 38.6 in | not published |
| S | chest 39 in, waist 31.5 in | L | S | chest 37.8 to 40.9 in, waist 33.1 to 36.2 in, hip 38.6 to 41.7 in | not published |
| M | chest 41 in, waist 33.5 in | XL | M | chest 40.9 to 44.1 in, waist 36.2 to 39.4 in, hip 41.7 to 44.9 in | not published |
| L | chest 43 in, waist 35.5 in | XL | L | chest 40.9 to 44.1 in, waist 36.2 to 39.4 in, hip 41.7 to 44.9 in | not published |
| XL | chest 45 in, waist 37.5 in | XXL | XL | chest 44.1 to 47.2 in, waist 39.4 to 42.5 in, hip 44.9 to 48 in | not published |
| XXL | chest 47 in, waist 39.5 in | XXL | XXL | chest 44.1 to 47.2 in, waist 39.4 to 42.5 in, hip 44.9 to 48 in | not published |
| XXXL | chest 49 in, waist 41.5 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
- Gymshark size guide, read on 2026-09-18. Gymshark on TrueToSize
- MUJI Japan sizing size guide, read on 2026-09-25.