MUJI to Gap size
The short answer
MUJI S is Gap XS by the two brands' own charts. 5 of 5 MUJI sizes land on a different label at Gap.
Both brands publish the body chest each size is cut for, so every row matches a chest, not a letter.
On 1 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.
| MUJI Japan sizing | MUJI builds it for | Gap, by chart | Same label | Gap builds it for | Gap also prints |
|---|---|---|---|---|---|
| XS | chest 29.9 to 33.1 in, waist 25.2 to 28.4 in, hip 30.7 to 33.9 in | not made | XS | not published | not published |
| S | chest 31.5 to 34.7 in, waist 26.8 to 29.9 in, hip 32.3 to 35.4 in | XS | S | chest 35 to 36 in, neck 13.5 to 14 in, sleeve 31 to 32 in | not published |
| M | chest 34.7 to 37.8 in, waist 29.9 to 33.1 in, hip 35.4 to 38.6 in | XS | M | chest 35 to 36 in, neck 13.5 to 14 in, sleeve 31 to 32 in | not published |
| L | chest 37.8 to 40.9 in, waist 33.1 to 36.2 in, hip 38.6 to 41.7 in | M | L | chest 39 to 41 in, neck 15 to 15.5 in, sleeve 33 to 34 in | not published |
| XL | chest 40.9 to 44.1 in, waist 36.2 to 39.4 in, hip 41.7 to 44.9 in | L | XL | chest 42 to 44 in, neck 16 to 16.5 in, sleeve 34 to 35 in | not published |
| XXL | chest 44.1 to 47.2 in, waist 39.4 to 42.5 in, hip 44.9 to 48 in | XL | XXL | chest 45 to 48 in, neck 17 to 17.5 in, sleeve 35 to 35.5 in | 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
- MUJI Japan sizing size guide, read on 2026-09-25.
- Gap size guide, read on 2026-09-18. Gap on TrueToSize