Smartwool to Onzie leggings size
The short answer
Smartwool S is Onzie M/L by the two brands' own charts. 5 of 5 Smartwool sizes land on a different label at Onzie.
Both brands publish the body waist each size is cut for, so every row matches a waist, not a tag.
On 3 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.
| Smartwool | Smartwool builds it for | Onzie, by chart | Same label | Onzie builds it for | Onzie also prints |
|---|---|---|---|---|---|
| S | waist 29 to 31 in, hip 36 to 38 in | M/L | X/S | waist 28 to 31 in, hip 38 to 40 in | US numeric 6-8 |
| M | waist 32 to 34 in, hip 39 to 41 in | L/L | S/M | waist 31 to 33 in, hip 40 to 42 in | US numeric 10-12 |
| L | waist 35 to 37 in, hip 42 to 44 in | XL | M/L | waist 34 to 37 in, hip 43 to 45 in | US numeric 14-16 |
| XL | waist 38 to 40 in, hip 45 to 48 in | 1X | XL | waist 38 to 40 in, hip 46 to 48 in | US numeric 16-18 |
| XXL | waist 41 to 44 in, hip 49 to 51 in | 1X | not published | waist 38 to 40 in, hip 46 to 48 in | US numeric 16-18 |
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
- Smartwool size guide, read on 2026-09-18.
- Onzie size guide, read on 2026-09-18.