Cycling Shorts/Underpants Size Chart:

 Size Waist Height Weight
S 25" - 27" (68 - 72 cm) 5' 3" - 5' 6" (160 - 168 cm) 110 - 121 lbs (50-55 kg)
M 28" - 30" (74 - 78 cm) 5' 5" - 5' 8" (164 - 172 cm) 121 - 143 lbs (55-65 kg)
L 31" - 33" (80 - 84 cm) 5' 6" - 5' 8" (168 - 172 cm) 143 - 154 lbs (65-70 kg)
XL 34" - 36" (86 - 90 cm) 5' 7" - 5' 11" (170 - 180 cm) 154 - 170 lbs (70-77 kg)
2XL 37" - 39" (92 - 96 cm) 5' 8" - 6'  (173 - 183 cm) 170 - 187 lbs (77-85 kg)
3XL 39"+ (100+ cm) 6'+ (183+ cm) 85+ kg (187+ lbs)