New technology that includes 3D body scanning, digital virtual human, and digital virtual garments has had a significant impact on the current apparel industry. Virtual simulation technology enables the visualization of a 3D virtual garment on a virtual avatar so that consumers can try on garments with their virtual avatars before purchasing. However, the manual virtual avatar provided for online apparel shopping currently has revealed limitations on the different body sizes and shapes of customers. This study analyzes the process of designing the automatic virtual avatar and the manual virtual avatar using OptiTex software; in addition, the study compares the practicality of the automatic virtual avatar with that of the manual virtual avatar. Data was examined by evaluating how much each virtual avatar is similar to the real body and how well it matched the needs of the current apparel industry. In the study, Avatar 1 was automatically created from three-dimensional body scan data and Avatar 2 was manually created from body measurements. The virtual avatar images laid over a real body image and the results were evaluated by comparing the simulated sizes of virtual avatars with those of a real body. Consequently, Avatar 1 was evaluated as more similar to the real body than Avatar 2 in all five body shapes. This study illustrates that an automatic virtual avatar might solve the fit problem that is the most common reason for a high return rate for online shopping. The results show that future virtual simulation technology needs to be improved for the practicality of the virtual avatars.