Basketball Game Length
Length of Quarters and Halves
In international competitions that use FIBA rules, there are 10-minute quarters. In men's college basketball, there are no quarters, only two 20-minute halves. Women's college basketball uses four 10-minute quarters.
In most high school competitions, there are four eight-minute quarters, making two 16-minute halves.
These quarter and half lengths represent the time on the game clock, which stops at every dead ball, timeout, and made basket when there is a certain amount of time left (final two minutes and overtime in college, final minute and overtime in the NBA).
Each team is allotted a specified number of timeouts to be used throughout each game. Teams use timeouts to stop the game clock, let players rest, or stop the other team's momentum during a game. You can read more about timeouts in the Basketball Timeouts tutorial.
The timeout duration for college, FIBA, and the NBA differ. In the NBA, each team gets six timeouts per game, four of which are mandatory due to being television timeouts. In the FIBA rules, there are five timeouts in total, with two coming in the first half and three coming in the second half. However, there are only two timeouts available in the last two minutes of the fourth quarter. There is also only one timeout per overtime period, rather than two timeouts that are allowed in the NBA.
In college basketball, each team is allowed one 60-second timeout and three 30-second timeouts in a game that is broadcasted. A maximum of three 30-second timeouts can be carried over into the second half. There are also media timeouts that take time from the game being played. These are called by the referees and only occur during stoppages of play (so that they will not interrupt a play).
Teams often resort to fouling to try and stop the clock, hopefully giving the trailing team a chance to win the game.
Complete duration of a basketball game
The length of a basketball game is dependent on many different factors, including the number of timeouts used, number of television timeouts, and fouls, among other things. These factors are independent from the game clock; for example, a free throw shooter may take up to 10 seconds per attempt and these seconds occur while the game clock is stopped.
In all, televised college and professional basketball games last about 2 hours and 15 minutes of real time, on average. High school games typically last about 2 hours.