This research aims to analyze jeans possession and perceptions of jeans' fit among women in their 20s to help improve the accuracy of purchase decisions in online shopping and to provide basic data necessary to overcome limits in the fit conveyance method of online shopping malls. A sample of 149 females in their 20s was divided into two groups according to height, waist size, and interest in fashion, and several factors were analyzed: jeans possession status, the fit of purchased jeans, the reason for purchase, and the perception of jeans' fit. The results are as follows. The group with a high interest in fashion owned more skinny jeans, and there was a higher frequency of purchasing skinny jeans during the last year among those with a height of 160 cm or more, a waist size of less than 27 inches, and a high interest in fashion. Of the respondents, 92.6% accurately understood skinny fit, 51.7% understood straight fit, and 56.4% understood regular fit. There was no significant difference in the perception of skinny fit or regular fit, but straight fit was better understood by the group with a waist size of 27 inches or more. Thus, by providing accurate size information and analyzing the body shapes of consumers, online shopping malls will be able to increase customer satisfaction with pants of various fits to reduce the rate of returns.