Please measure around the largest part of your chest to measure its circumference. 

Please allow ±3cm from the idea fit to find your perfect fit.

All Possenia products are designed to be race fit 'ideally' thus, snug fitting and streamlined along the body. If you prefer a looser fit, take one size up. If you prefer a super race-fit, look at the higher ends of the ideal fit i.e if you're 98cm around the chest and want a serious race-fit, take an S.