Curious how long it takes to watch a basketball game? That depends on whether it is professional, college, or high school. If you use live streaming or 4K HDR you can take it with you wherever you need to be.
NBA games are 48 minutes in duration. They consist of four quarters of 12 minutes each and a halftime period of 15 minutes. This applies across the league no matter of it is the Boston Celtics or LA Lakers or Dallas Mavericks or Houston Rockets. Depending on the specific TV coverage, there can be slight to modest variations in the length of halftime.
The NBA Commissioner, Adam Silver, has made it a priority to try and reduce the time overall it takes to execute an entire NBA game. Silver would like to fit each NBA game into a two hour window.
The WNBA plays four ten minute quarters.
College basketball plays two twenty minute halves.
High school athletics vary by location, but the general format is two twenty minute halves.