The top of the hoop is 10 feet (305 cm) above the ground. Regulation backboards are 6 feet (183 cm) wide by 3.5 feet (107 cm) tall. All basketball rims (hoops) are 18 inches (46 cm) in diameter. The inner rectangle on the backboard is 24 inches (61 cm) wide by 18 inches (46 cm) tall.Click to see full answer. In this way, what is the size of a high school basketball backboard? The Backboard and Rim: Regulation backboards are 6 feet wide (72 inches) by 42 inches tall. All basketball rims (hoops) are 18 inches in diameter. The inner square on the backboard is 24 inches wide by 18 inches tall.Additionally, what is the height of a basketball backboard? For junior high, high school, NCAA, WNBA, NBA and FIBA, the rim is exactly 10 feet off the ground. Rims at every level of play are 18 inches in diameter. Backboards are also the same size at each of these levels. A regulation backboard measures 6 feet wide and 42 inches (3.5 feet) tall. People also ask, what is NBA size backboard? Backboards range from 44″ to 72″. Let’s first began with the NBA regulation size. They are 72 inches wide, 42 inches high, half an inch thick and of course are made of glass. There is no need to have a 72 inch backboard.What is a standard backboard size?The top of the hoop is 10 feet (305 cm) above the ground. Regulation backboards are 72 inches (183 cm) wide by 42 inches (110 cm) tall. All basketball rims (hoops) are 18 inches (46 cm) in diameter. The inner rectangle on the backboard is 24 inches (61 cm) wide by 18 inches (46 cm) tall.