Spanx to Onzie leggings size
The short answer
Spanx XS is Onzie X/S by the two brands' own charts. 5 of 7 Spanx 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.
| Spanx | Spanx builds it for | Onzie, by chart | Same label | Onzie builds it for | Onzie also prints |
|---|---|---|---|---|---|
| XS | waist 25 to 27 in, hip 34 to 36 in | X/S | not published | waist 24 to 26 in, hip 33 to 35 in | US numeric 0-2 |
| S | waist 27 to 29 in, hip 36 to 38 in | S/M | X/S | waist 26 to 28 in, hip 36 to 38 in | US numeric 2-6 |
| M | waist 29 to 31 in, hip 38 to 40 in | M/L | S/M | waist 28 to 31 in, hip 38 to 40 in | US numeric 6-8 |
| L | waist 31 to 33.5 in, hip 40 to 42.5 in | L/L | M/L | waist 31 to 33 in, hip 40 to 42 in | US numeric 10-12 |
| XL | waist 33.5 to 36 in, hip 42.5 to 45 in | XL | XL | waist 34 to 37 in, hip 43 to 45 in | US numeric 14-16 |
| 1X | waist 36 to 39 in, hip 45 to 48 in | 1X or XL | 1X | waist 38 to 40 in, hip 46 to 48 in | US numeric 16-18 |
| 2X | waist 39 to 42 in, hip 48 to 51 in | 1X | not published | waist 38 to 40 in, hip 46 to 48 in | US numeric 16-18 |
| 3X | waist 42 to 45 in, hip 51 to 54 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
- Spanx size guide, read on 2026-09-18. Spanx on TrueToSize
- Onzie size guide, read on 2026-09-18.