Sandro to Under Armour clothing size

The short answer

Sandro 34 is Under Armour XXS 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 Sandro size read across to Under Armour. FR sizes on the left, Letter on the right.
Sandro	Sandro builds it for	Under Armour, by chart	Same label	Under Armour builds it for	Under Armour also prints
34	bust 32 in, waist 25 in, hip 35 in	XXS	XS	bust 31 to 32.5 in, waist 24.5 to 25.5 in	US 00
36	bust 34 in, waist 27 in, hip 36 in	SM	not published	bust 33.5 to 36 in, waist 27 to 29 in	US 4-6
38	bust 35 in, waist 28 in, hip 38 in	SM	not published	bust 33.5 to 36 in, waist 27 to 29 in	US 4-6
40	bust 37 in, waist 30 in, hip 39 in	MD	not published	bust 36 to 38 in, waist 29 to 31 in	US 8-10
42	bust 39 in, waist 31 in, hip 41 in	LG	XL	bust 38 to 41 in, waist 31 to 34 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.

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Sources

Sandro size guide, read on 2026-09-18.
Under Armour size guide, read on 2026-09-18. Under Armour on TrueToSize

Under Armour to Sandro