A professional basketball game in the National Basketball Association (NBA) consists of four quarters of 12 minutes each, making the game last for 48 minutes. College basketball consists of two halves of 20 minutes each, with a 40 minute game overall.
The length of a game varies according to the level and competition. The actual game takes much longer to play that the length of the quarters or halves due to stoppages in the play. Time is stopped for certain fouls, injuries, timeouts and breaks in-between play periods. A typical game will take approximately 2-3 hours to complete from start to finish.