Ultimate Direction Women's Running Vests Size Guide

Size	Ribs (Inches)	Ribs (Centimeters)
XS/SM	21-36	53.34-91.44
SM/MD	24-40	60.96-101.60
MD/LG	28-42	71.12-106.68
LG/XL	38-46	95.52-116.84

How to Measure:

RIBS: Measure around the bottom of your ribs.