Patagonia to Under Armour size
The short answer
Patagonia XXS is Under Armour XS by the two brands' own charts. 6 of 8 Patagonia sizes land on a different label at Under Armour.
Both brands publish the body chest each size is cut for, so every row matches a chest, not a letter.
| Patagonia | Patagonia builds it for | Under Armour, by chart | Same label | Under Armour builds it for | Under Armour also prints |
|---|---|---|---|---|---|
| XXS | chest 33 in, hip 32 in, sleeve 30 in | XS | not published | chest 31 to 34 in, waist 28 to 29 in | not published |
| XS | chest 35 in, hip 34 in, sleeve 32 in | SM | XS | chest 34 to 37 in, waist 29 to 31 in | not published |
| S | chest 37 in, hip 36 in, sleeve 33 in | SM | not published | chest 34 to 37 in, waist 29 to 31 in | not published |
| M | chest 40 in, hip 39 in, sleeve 34 in | MD | not published | chest 37 to 41 in, waist 31 to 34 in | not published |
| L | chest 44 in, hip 43 in, sleeve 35 in | LG | not published | chest 41 to 44 in, waist 34 to 37 in | not published |
| XL | chest 47 in, hip 46 in, sleeve 36 in | XL | XL | chest 44 to 48 in, waist 37 to 41 in | not published |
| XXL | chest 50 in, hip 49 in, sleeve 37 in | XXL | XXL | chest 48 to 52 in, waist 41 to 45.5 in | not published |
| XXXL | chest 56 in, hip 55 in, sleeve 37.5 in | 3XL | 3XL | chest 52 to 56 in, waist 45.5 to 50 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
- Patagonia size guide, read on 2026-09-18.
- Under Armour size guide, read on 2026-09-18. Under Armour on TrueToSize