The average American bedroom in new homes is between 120 and 150 square feet. Master bedrooms are typically much larger, averaging more than 200 square feet, without taking into account closet space or a bathroom.
Bedroom sizes are much bigger in newer construction than in homes built before the 1990s. Changes to the building code by the International Code Council have set standards on what the minimum size requirements are for a room to be declared a bedroom. The 2006 code R304 states that any habitable space must have no less than 7 linear feet of floor space in any horizontal direction. Every dwelling unit has to have at least one room that is 120 square feet or larger, and no habitable space is to be less than 70 square feet.