The best length, width and size of the bathroom vary from person to person, but generally speaking, a comfortable bathroom should have at least the following dimensions: 1. Length: more than 2.4 meters. Width:1.5m or more. Height: more than 2.4 meters. These dimensions can ensure that the bathroom has enough space to accommodate facilities such as washbasin, toilet, shower room or bathtub, and enough space to move and turn around. In addition, the width of the bathroom door should be wide enough to facilitate the entry and use of wheelchairs or people with limited mobility.