Backboard ( basketball ) - wikipedia Backboard ( basketball ) This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( May 2013 ) Typical professional hoop with backboard Typical privately owned basketball hoop with backboard A backboard is a piece of basketball equipment. It is a raised vertical board with an attached basket consisting of a net suspended from a hoop. It is made of a flat, rigid piece of, often Plexiglas or tempered glass which also has the properties of safety glass when accidentally shattered. It is usually rectangular as used in NBA, NCAA and international basketball. In recreational environments, a backboard may be oval or a fan - shape, particularly in non-professional games. 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. In professional and most higher college settings, the backboard is part of a portable stanchion that can be moved out of the way in other sports, though in most high schools and examples such as Stanford University 's Maples Pavilion, backboards are mounted as part of a suspended system using ceiling joists to support the goal and allow them to be put out of the way in the ceiling when not in use. The first glass backboard was used by the Indiana Hoosiers men 's basketball team at the Men 's Gymnasium at Indiana University. After the first few games at their new facility in 1917, spectators complained that they could not see the game because of opaque wooden backboards. As a result the Nurre Mirror Plate Company in Bloomington was employed to create new backboards that contained 1 ⁄ - inch - thick ( 3.8 cm ) plate glass so that fans could see games without an obstructed view. It was the first facility in the country to use glass backboards. Professional glass backboards used to break from 625 pounds ( 283 kg ) of force or more. Modern professional and higher - level college play backboards do not have the glass absorbing any weight to avoid breaking. References Jump up ^ http://www.nba.com/analysis/rules_1.html Oct 17 2006 4 : 32AM ^ Jump up to : Hiner, Jason ( 2005 ). Indiana University Basketball Encyclopedia. United States : Sports Publishing. p. 447. ISBN 1 - 58261 - 655 - 8. Jump up ^ rockboy1138 ( 2009 - 12 - 01 ), Sports Science puts NBA backboards to the test !, retrieved 2017 - 07 - 06 Basketball Outline of basketball General topics History of basketball James Naismith Variations of basketball Leagues Statistics Glossary of terms Index of articles Rules Bonus Jump ball Officials Turnover Violation 3 seconds Offense Defense 5 seconds Basket interference Carrying Double dribble Goaltending Shot clock Traveling Foul Flagrant Personal Technical Game play Air ball Alley - oop Assist Backboard shattering Ball hog Block Buzzer beater Cherry picking Dribble Crossover Dunk Euro step Fadeaway Fast break Fly Flop Jump shot Layup Finger roll Field goal Four - point play Free throw Hook shot Moves Pick and roll Positions Posterized Playbook Rebound Point Screen Back screen Slashing Steal Three - pointer Three - point play Uncontested shot Strategy General Sixth man Offense Continuity offense Flex Shuffle UCLA High Post Wheel Dribble drive motion Four corners Motion Princeton Run and gun Grinnell System Nellie Ball Small ball Triangle Defense 1 - 2 - 1 - 1 1 -- 3 -- 1 2 -- 3 zone Amoeba Box - and - one Double team Full - court press Hack - a-Shaq Jordan Rules Line Man - to - man Match - up zone Triangle - and - two Zone Equipment Backboard Ball Breakaway rim Court Half court Key Net Possession arrow Whistle Clothing Basketball sleeve Finger sleeve Air Jordan Chuck Taylor All - Stars Miscellaneous 100 - point scorers 50 -- 40 -- 90 club AAU All - Americans AAU champions Mikan Drill Player tracking Shootaround Tip drill Winning streaks Retrieved from `` https://en.wikipedia.org/w/index.php?title=Backboard_(basketball)&oldid=852780795 '' Categories : Basketball equipment Hidden categories : Articles needing additional references from May 2013 All articles needing additional references Talk About Wikipedia Azərbaycanca Bosanski Dansk Deutsch Français Polski Русский Српски / srpski Türkçe 中文 3 more Edit links This page was last edited on 31 July 2018, at 09 : 34 ( UTC ). About Wikipedia

Question: what is the diameter of an nba basketball hoop
Answer: 18 inches (46 cm)