A room referred to as a quarter-bath denotes the room includes only one fixture instead of the complete set of fixtures in a full bathroom. This is likely due to the smaller space of the room, which will not allow inclusion of the other fixtures. A 1/4 bath is also called a quarter-bath.
Definition of 1/4 Bath
A quarter-bath has only a single fixture. Out of the four fixtures possible, that one item is normally a toilet. The lone fixture inside a quarter-bath could also be a sink, however. In that case, the room is often referred to as a washroom, since users will only be using it to wash their hands or faces.
Comparison to Other Bathrooms
For a room to be called a full bathroom, it has to include all four fixtures, including the toilet, wash basin or sink, a bathtub and shower. A master bath contains all of these fixtures and is also adjacent to the home's master bedroom. A room that lacks any one of these four fixtures--such as a room that includes only a toilet, sink and shower--is called a 3/4 bath. Take away another fixture, leaving just a toilet and sink inside the room, and it becomes a 1/2 bath.
Among the different types of bathrooms, a quarter-bath offers the least amount of room. This imposes a definite limit on the amount of interior decorating and embellishment inside. Wall decorations may be a more viable choice than items placed on the floor, nearly all of which is needed around the toilet for user comfort.
Because it is the lone fixture inside a 1/4 bath, you may be able to install any size toilet inside the room. If space is a concern because the room is very small, a toilet with a round instead of elongated bowl saves you at least 2 inches of space around the fixture. Because of the space limitation, a wall toilet paper holder may be a better fit than a freestanding holder. An over-the-toilet shelf provides vertical space to store needed items such as toilet paper, magazines or photos.