Fashion trends that are moving very quickly have a significant influence on consumer lifestyles which then give birth to a culture of consumerism among society. This consumer behavior requires responses from various parties to create more sustainable consumption. Consumers have a strong role in encouraging sustainable consumption in the fashion sphere by implementing the Capsule Wardrobe concept which requires users to mix and match a limited number of fashion items to be used in various situations over a long period of time. From this, sustainable practice efforts are also being made on the part of the designer by looking for alternatives or design strategies so that the product can meet the needs of Capsule Wardrobe players by implementing a convertible system on fashion products as a way to realize sustainability. A convertible system refers to a change in appearance or function, it can be worn in a variety of situations providing versatile design and functionality and adapts to rapidly changing trends so that a longer product life is expected. In the context of consumerism, women are the largest consumers in the fashion sector and tend to be more consumptive than men. However, women can also fulfill their role by contributing to sustainable fashion by implementing the Capsule Wardrobe concept. Since the Capsule Wardrobe concept focuses on a limited number of clothing items, it is necessary to add variety and personal impressions through accessories to create a different look and add interest to the clothes. From the data obtained, it is known that bags are the main need for women to complete their accessory needs in the Capsule Wardrobe concept. From this, this design is aimed at female consumers by developing fashion accessory products in the form of convertible bags that can be changed in function and appearance as an effort to meet the needs and desires of users and create sustainable fashion. By implementing a convertible system, a bag product is obtained that offers changes in appearance and function that can influence users to use the product for a long time. Convertible bag products create a versatile mix-and-match look so users can match a variety of clothing styles and use them for a variety of different situations.