Reiss to lululemon clothing size

The short answer

Reiss 10 is lululemon M by the two brands' own charts.

Both brands publish the body bust each size is cut for, so every row matches a bust, not a letter or a number.

Every Reiss size read across to lululemon. UK sizes on the left, Letter on the right.
Reiss	Reiss builds it for	lululemon, by chart	Same label	lululemon builds it for	lululemon also prints
4	bust 31 in, waist 24 in, hip 34 in	XS	XS	bust 31 to 32 in	US 4
6	bust 32 in, waist 25 in, hip 35 in	XS	XS	bust 31 to 32 in	US 4
8	bust 33 in, waist 26 in, hip 36 in	S	S	bust 33 to 34 in	US 6
10	bust 35 in, waist 28 in, hip 38 in	M	S	bust 35 to 36 in	US 8
12	bust 37 in, waist 30 in, hip 40 in	L	M	bust 37 to 38.5 in	US 10
14	bust 39 in, waist 31.5 in, hip 42 in	L or XL	M	bust 37 to 38.5 in	US 10
16	bust 41 in, waist 33.5 in, hip 44 in	XL	L	bust 40 to 42 in	US 12-14
18	bust 43 in, waist 36 in, hip 46.5 in	XL or 1X	L	bust 40 to 42 in	US 12-14

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, not a fit. We do not collect fit reports for this category yet, so this table is the two brands' own claims and nothing more.

Open in the converter Add an item you own

Sources

Reiss size guide, read on 2026-09-18.
lululemon size guide, read on 2026-09-18. lululemon on TrueToSize

lululemon to Reiss