When choosing a chandelier for a high-ceilinged room, it's important to consider the size and scale of the fixture. A general rule of thumb is to choose a chandelier with a diameter that is one-third the width of the room. For example, if your room is 18 feet wide, a chandelier with a diameter of 6 feet would be a good choice. It's also important to consider the height of the ceiling, as well as the overall style and design of the room. A chandelier that complements the existing decor and architecture can create a cohesive and stylish look while ensuring that the light is distributed evenly throughout the space.