The official height of a regulation NBA basketball hoop is 10 feet from the floor, and the backboard extends another 3.5 feet vertically and 6 feet horizontally. The hoop is 18 inches in diameter. The height of the hoop is standard across all levels of play.
Since the sport's invention by Dr. Naismith in 1891, the height of the basket has been 10 feet. The height was chosen based on the dimensions of the Springfield College gym. At times, there have been requests to alter the height of the basket temporarily. Dwight Howard wished to attempt a dunk at the height of 12 feet during the 2008 dunk competition, but his request was refused by the league.