Whistles to Under Armour clothing size
The short answer
Whistles 14 is Under Armour MD by the two brands' own charts.
Both brands publish the body bust each size is cut for, so every row matches a bust, not a letter or a number.
| Whistles | Whistles builds it for | Under Armour, by chart | Same label | Under Armour builds it for | Under Armour also prints |
|---|---|---|---|---|---|
| 04 | bust 30 in, waist 23.5 in, hip 34.5 in | not made | not published | not published | not published |
| 06 | bust 31 in, waist 24.5 in, hip 35.5 in | XXS | not published | bust 31 to 32.5 in, waist 24.5 to 25.5 in | US 00 |
| 08 | bust 32 in, waist 25.5 in, hip 36.5 in | XXS | not published | bust 31 to 32.5 in, waist 24.5 to 25.5 in | US 00 |
| 10 | bust 34 in, waist 27.5 in, hip 38.5 in | SM | not published | bust 33.5 to 36 in, waist 27 to 29 in | US 4-6 |
| 12 | bust 36 in, waist 29.5 in, hip 40.5 in | MD | not published | bust 36 to 38 in, waist 29 to 31 in | US 8-10 |
| 14 | bust 38 in, waist 31.5 in, hip 42.5 in | MD | not published | bust 36 to 38 in, waist 29 to 31 in | US 8-10 |
| 16 | bust 40 in, waist 33.5 in, hip 44.5 in | LG | not published | bust 38 to 41 in, waist 31 to 34 in | US 12-14 |
| 18 | bust 42.5 in, waist 35.5 in, hip 46.5 in | XL | not published | bust 41 to 44 in, waist 34 to 37 in | US 16 |
| 20 | bust 45 in, waist 38 in, hip 49 in | XXL | not published | 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
- Whistles size guide, read on 2026-09-18.
- Under Armour size guide, read on 2026-09-18. Under Armour on TrueToSize