Always measure in length first, then breadth, and lastly height. It is a bed, for instance, if it is 75 inches long, 31 inches broad, and 17 inches high. On the other hand, it's a wardrobe if it measures 75 inches high, 31 inches wide, and 17 inches deep. Standard bed sizes include queen, twin, single, and king, in addition to a few additional interesting configurations.