Nike to Under Armour clothing size
The short answer
Nike XS is Under Armour XXS by the two brands' own charts. 4 of 6 Nike sizes land on a different label at Under Armour.
Both brands publish the body bust each size is cut for, so every row matches a bust, not a letter or a number.
| Nike | Nike builds it for | Under Armour, by chart | Same label | Under Armour builds it for | Under Armour also prints |
|---|---|---|---|---|---|
| XXS | bust 27.5 to 29.5 in, waist 21.3 to 23.5 in, hip 30.5 to 33 in | not made | XXS | not published | not published |
| XS | bust 29.5 to 32.5 in, waist 23.5 to 26 in, hip 33 to 35.5 in | XXS | XS | bust 31 to 32.5 in, waist 24.5 to 25.5 in | US 00 |
| S | bust 32.5 to 35.5 in, waist 26 to 29 in, hip 35.5 to 38.5 in | SM | not published | bust 33.5 to 36 in, waist 27 to 29 in | US 4-6 |
| M | bust 35.5 to 38 in, waist 29 to 31.5 in, hip 38.5 to 41 in | MD | not published | bust 36 to 38 in, waist 29 to 31 in | US 8-10 |
| L | bust 38 to 41 in, waist 31.5 to 34.5 in, hip 41 to 44 in | LG | not published | bust 38 to 41 in, waist 31 to 34 in | US 12-14 |
| XL | bust 41 to 44.5 in, waist 34.5 to 38.5 in, hip 44 to 47 in | XL | XL | bust 41 to 44 in, waist 34 to 37 in | US 16 |
| XXL | bust 44.5 to 48.5 in, waist 38.5 to 42.5 in, hip 47 to 50 in | XXL | XXL | bust 44 to 47 in, waist 37 to 40 in | US 18 |
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
- Nike size guide, read on 2026-09-18. Nike on TrueToSize
- Under Armour size guide, read on 2026-09-18. Under Armour on TrueToSize