The length of an evening dress can vary depending on the formality of the event and personal preference. Traditionally, evening dresses are floor-length, reaching the ankle or the floor, giving the dress a formal and elegant look. However, more modern designs may be shorter, such as midi-length or even mini-length, particularly for cocktail events. The length of the dress can also be determined by the style and cut of the dress, with high-low or asymmetrical hemlines being popular choices. Ultimately, the length of the dress should be chosen based on the occasion, personal style, and what makes the wearer feel comfortable and confident.