Onzie to Under Armour leggings size
The short answer
Onzie X/S is Under Armour XXS by the two brands' own charts. 5 of 6 Onzie 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.
| Onzie | Onzie builds it for | Under Armour, by chart | Same label | Under Armour builds it for | Under Armour also prints |
|---|---|---|---|---|---|
| X/S | waist 24 to 26 in, hip 33 to 35 in | XXS | not published | waist 24.5 to 25.5 in, hip 33 to 34.5 in | US numeric 00 |
| S/M | waist 26 to 28 in, hip 36 to 38 in | XS | not published | waist 25.5 to 27 in, hip 34.5 to 36 in | US numeric 0-2 |
| M/L | waist 28 to 31 in, hip 38 to 40 in | MD | not published | waist 29 to 31 in, hip 38 to 40 in | US numeric 8-10 |
| L/L | waist 31 to 33 in, hip 40 to 42 in | LG | not published | waist 31 to 34 in, hip 40 to 43 in | US numeric 12-14 |
| XL | waist 34 to 37 in, hip 43 to 45 in | XL | XL | waist 34 to 37 in, hip 43 to 46 in | US numeric 16 |
| 1X | waist 38 to 40 in, hip 46 to 48 in | XXL | 1X | waist 37 to 40 in, hip 46 to 49 in | US numeric 18 |
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
- Onzie size guide, read on 2026-09-18.
- Under Armour size guide, read on 2026-09-17. Under Armour on TrueToSize