A medium sized room for home theater is typically between 200 and 400 square feet. The size of the room will dictate how many speakers you need, as well as the size of the television or projector screen. In a smaller room, you may only need a few speakers, while a larger room will require more. The type of furniture in the room will also play a role in how it looks and feels. A home theater should have comfortable seating that allows everyone to see the screen clearly. You may also want to consider adding some sound-absorbing materials to help create the perfect viewing experience.