Four by eight is a specific measurement that describes the size of a sheet of plywood or other building material. The term four by eight can also be referred to as a sheet, panel or board and can be used interchangeably to describe the same size. Other synonyms for four by eight include 48 inches by 96 inches, 4 feet by 8 feet or 1219 millimeters by 2438 millimeters. The use of these synonyms is important in the construction industry as it helps to avoid confusion and ensures that accurate measurements are used when cutting and installing materials.