Gymshark to American Eagle size
The short answer
Gymshark XS is American Eagle S by the two brands' own charts. 4 of 7 Gymshark 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 2 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 | American Eagle, by chart | Same label | American Eagle builds it for | American Eagle also prints |
|---|---|---|---|---|---|
| XS | chest 37 in, waist 29.5 in | S | XS | chest 37 to 39 in, neck 14.5 to 15 in, sleeve 32.5 in | not published |
| S | chest 39 in, waist 31.5 in | S | S | chest 37 to 39 in, neck 14.5 to 15 in, sleeve 32.5 in | not published |
| M | chest 41 in, waist 33.5 in | M | M | chest 40 to 42 in, neck 15 to 15.5 in, sleeve 33.5 in | not published |
| L | chest 43 in, waist 35.5 in | L | L | chest 43 to 45 in, neck 15.5 to 16 in, sleeve 34.5 in | not published |
| XL | chest 45 in, waist 37.5 in | L | XL | chest 43 to 45 in, neck 15.5 to 16 in, sleeve 34.5 in | not published |
| XXL | chest 47 in, waist 39.5 in | XL | XXL | chest 46 to 48 in, neck 16.5 to 17 in, sleeve 35.5 in | not published |
| XXXL | chest 49 in, waist 41.5 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
- Gymshark size guide, read on 2026-09-18. Gymshark on TrueToSize
- American Eagle size guide, read on 2026-09-18. American Eagle on TrueToSize