A National Basketball Association regulation backboard measures 72 inches horizontally and 42 inches vertically. Official NBA rules also stipulate that the backboard must be flat and transparent.
The backboard must be marked with a white rectangle centered behind the hoop. The rectangle must measure 2 inches in width, 24 inches horizontally and 18 inches vertically. The backboard must be positioned so that the hoop attached to the board is exactly 10 feet above the ground. The basketball rim measures 18 inches in diameter. The material used to create the backboard has varied greatly since the sport's inception in the 1890s, when wooden backboards were used. Most major basketball leagues now use Plexiglas backboards.