Smartwool to SET Active leggings size

The short answer

Smartwool S is SET Active M by the two brands' own charts. 4 of 5 Smartwool sizes land on a different label at SET Active.

Both brands publish the body waist each size is cut for, so every row matches a waist, not a tag.

Every Smartwool size read across to SET Active. Letter sizes on the left, Letter on the right.
Smartwool	Smartwool builds it for	SET Active, by chart	Same label	SET Active builds it for	SET Active also prints
S	waist 29 to 31 in, hip 36 to 38 in	M	S	waist 28 to 30 in	US numeric 8-10
M	waist 32 to 34 in, hip 39 to 41 in	L	M	waist 31 to 33 in	US numeric 12-14
L	waist 35 to 37 in, hip 42 to 44 in	XL	L	waist 34 to 36 in	US numeric 16-18
XL	waist 38 to 40 in, hip 45 to 48 in	XXL	XL	waist 37 to 40 in	US numeric 20-22
XXL	waist 41 to 44 in, hip 49 to 51 in	XXL	XXL	waist 37 to 40 in	US numeric 20-22

Tinted rows change label or sit between two sizes. Read from the two charts only; no formula and no averaging.

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.

Open in the converter Add an item you own

Sources

Smartwool size guide, read on 2026-09-18.
SET Active size guide, read on 2026-09-18.

SET Active to Smartwool