Basketball Game Clock Rules

Everything in basketball revolves around time. The whole point of the game is to see who can score more points within a certain interval. Understanding the clock rules is essential no matter what level of basketball you're playing, coaching or watching. The rules for timing vary for high school, college and professional basketball.

Game Length

• High school games consist of four quarters lasting eight minutes each, and four minute overtime periods if necessary
• College basketball rules call for two 20-minute halves, with five minute overtime periods if necessary
• NBA games are divided into 12-minute quarters, with five minute overtime periods if necessary
  

Starting and Stopping Clock

The clock starts when a player touches the ball after the official tosses it for the initial jump ball.

The clock is only stopped by the officials to indicate a number of things, including:

1. A foul
   
2. A timeout
   
3. A violation
   
4. Ball going out of bounds and away from play
5. An injured player is down on the floor

The clock starts again when it's touched inbounds after a throw-in, or when a player touches the ball on a rebound after a missed free throw.

End of Game Rules

Some timing rules change toward the end of the game:

• The clock stops during the last minute of the second half plus overtime periods in college after a made basket, and starts again once a player touches the ball inbounds following the ensuing throw-in
  • In the NBA, this rule applies to the last two minutes of the fourth quarter and any overtime periods
  • There is no similar rule in high school basketball

Last Shot Rule

In high school and college basketball, if there are three-tenths of a second or less left on the clock, players may not catch and shoot the ball for a successful field goal. A player may only tap or deflect the ball into the basket for the shot to be counted. A shot will only be counted if it leaves the shooter's hand before time expires.