GU to American Eagle size
The short answer
GU S is American Eagle XS by the two brands' own charts. 6 of 6 GU sizes land on a different label at American Eagle.
Both brands publish the body chest each size is cut for, so every row matches a chest, not a letter.
On 4 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.
| GU Japan sizing | GU builds it for | American Eagle, by chart | Same label | American Eagle builds it for | American Eagle also prints |
|---|---|---|---|---|---|
| XS | chest 29.9 to 33.1 in, waist 25.2 to 28.4 in | not made | XS | not published | not published |
| S | chest 31.5 to 34.7 in, waist 26.8 to 29.9 in | XS | S | chest 35 to 36 in, neck 13.5 to 14 in, sleeve 31.5 in | not published |
| M | chest 34.7 to 37.8 in, waist 29.9 to 33.1 in | XS | M | chest 35 to 36 in, neck 13.5 to 14 in, sleeve 31.5 in | not published |
| L | chest 37.8 to 40.9 in, waist 33.1 to 36.2 in | S or M | L | chest 37 to 39 in, neck 14.5 to 15 in, sleeve 32.5 in | not published |
| XL | chest 40.9 to 44.1 in, waist 36.2 to 39.4 in | L or M TALL | XL | chest 43 to 45 in, neck 15.5 to 16 in, sleeve 34.5 in | not published |
| XXL | chest 44.1 to 47.2 in, waist 39.4 to 42.5 in | XL or L TALL | XXL | chest 46 to 48 in, neck 16.5 to 17 in, sleeve 35.5 in | not published |
| 3XL | chest 47.2 to 50.4 in, waist 42.5 to 45.7 in | XXL | XXXL | chest 49 to 51 in, neck 17 to 18 in, sleeve 36.5 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
- GU Japan sizing size guide, read on 2026-09-25.
- American Eagle size guide, read on 2026-09-18. American Eagle on TrueToSize