This article explains the basics of the Japanese clothing size system and answers the question: what is the average dress size for a woman in Japan? According to recent surveys conducted by fashion retailers, the average dress size for a woman in Japan is L-LL (Large-Large Large). Age, body type and lifestyle choices all play an important role when it comes determining one’s exact Japanese clothing size. To find your exact Japanese clothing size you should take three measurements: your height (in centimeters), your bust circumference (in centimeters) and your waist circumference (in centimeters).