Onzie to Gymshark leggings size
The short answer
Onzie X/S is Gymshark XXS or XS by the two brands' own charts. 5 of 5 Onzie sizes land on a different label at Gymshark.
Both brands publish the body waist each size is cut for, so every row matches a waist, not a tag.
| Onzie | Onzie builds it for | Gymshark, by chart | Same label | Gymshark builds it for | Gymshark also prints |
|---|---|---|---|---|---|
| X/S | waist 24 to 26 in, hip 33 to 35 in | XXS or XS | not published | waist 24 in, hip 35.5 in | US numeric 2-4 |
| S/M | waist 26 to 28 in, hip 36 to 38 in | XS or S | not published | waist 26 in, hip 37.5 in | US numeric 4-6 |
| M/L | waist 28 to 31 in, hip 38 to 40 in | M | not published | waist 30 in, hip 41.5 in | US numeric 8-10 |
| L/L | waist 31 to 33 in, hip 40 to 42 in | L | not published | waist 32 in, hip 43.5 in | US numeric 10-12 |
| XL | waist 34 to 37 in, hip 43 to 45 in | XXL | XL | waist 36 in, hip 47.7 in | US numeric 14-16 |
| 1X | waist 38 to 40 in, hip 46 to 48 in | not made | not published | not published | not published |
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.
- Gymshark size guide, read on 2026-09-17. Gymshark on TrueToSize