Under Armour Underwear Sizing
 
Men's Size Waist (inches) Waist (cm)
S 28-29 71-74
M 30-32 76-81
L 34-36 86-91
XL 38-40 97-102
XXL 42-44 107-112
XXXL 46-48 117-122
 
Youth Sizes Child Size Chest Waist Height
Youth SM 8 26-28 in
66-71 cm
23-24 in
58-61 cm
50-54 in
127-137 cm
Youth MD 10-12 28-30 in
71-76 cm
25-26 in
64-66 cm
54-59 in
137-150 cm
Youth LG 14-16 30-32 in
76-81 cm
26-27 in
66-69 cm
59-63 in
150-160 cm
Youth XL 18-20 32-34 in
81-86 cm
28-29 in
71-74 cm
63-67 in
160-170 cm
See our complete fitting guide here