Nike to Under Armour leggings size
The short answer
Nike XS is Under Armour XXS by the two brands' own charts. 8 of 11 Nike sizes land on a different label at Under Armour.
Both brands publish the body waist each size is cut for, so every row matches a waist, not a tag.
On 1 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.
| Nike | Nike builds it for | Under Armour, by chart | Same label | Under Armour builds it for | Under Armour also prints |
|---|---|---|---|---|---|
| XXS | waist 21.3 to 23.5 in, hip 30.5 to 33 in | not made | XXS | not published | not published |
| XS | waist 23.5 to 26 in, hip 33 to 35.5 in | XXS | XS | waist 24.5 to 25.5 in, hip 33 to 34.5 in | US numeric 00 |
| S | waist 26 to 29 in, hip 35.5 to 38.5 in | SM | not published | waist 27 to 29 in, hip 36 to 38 in | US numeric 4-6 |
| M | waist 29 to 31.5 in, hip 38.5 to 41 in | MD | not published | waist 29 to 31 in, hip 38 to 40 in | US numeric 8-10 |
| L | waist 31.5 to 34.5 in, hip 41 to 44 in | LG | not published | waist 31 to 34 in, hip 40 to 43 in | US numeric 12-14 |
| XL | waist 34.5 to 38.5 in, hip 44 to 47 in | XL | XL | waist 34 to 37 in, hip 43 to 46 in | US numeric 16 |
| XXL | waist 38.5 to 42.5 in, hip 47 to 50 in | 1X | XXL | waist 39 to 43.5 in, hip 47 to 50.5 in | US numeric 16W-18W |
| 0X | waist 40 to 43 in, hip 48 to 51 in | 3XL | not published | waist 40 to 43 in, hip 49 to 52 in | US numeric 20 |
| 1X | waist 43 to 45.5 in, hip 51 to 54 in | 2X | 1X | waist 43.5 to 48.5 in, hip 50.5 to 54.5 in | US numeric 20W-22W |
| 2X | waist 45.5 to 49 in, hip 54 to 57 in | 2X | 2X | waist 43.5 to 48.5 in, hip 50.5 to 54.5 in | US numeric 20W-22W |
| 3X | waist 49 to 53 in, hip 57 to 61 in | 3X | 3X | waist 48.5 to 53 in, hip 54.5 to 58 in | US numeric 24W-26W |
| 4X | waist 53 to 57 in, hip 61 to 65 in | 3X | not published | waist 48.5 to 53 in, hip 54.5 to 58 in | US numeric 24W-26W |
What wearers say
Charts describe a garment. People who own both brands describe a fit, and their answer ranks above this table once five of them stand behind it. Pick your size in the converter to see whether there are enough yet.
Sources
- Nike size guide, read on 2026-09-17. Nike on TrueToSize
- Under Armour size guide, read on 2026-09-17. Under Armour on TrueToSize