On average, a Major League Baseball game has nine innings. But in 2021, there are now two seven-inning doubleheaders, which is a full game. Also, baseball games can go into extra innings to decide a winner, so regular season and postseason games usually last nine innings.
Baseball games usually last nine innings, but there is no time limit on how long it takes to play all nine innings. Since there is no clock in baseball, the length of each game varies from one to the next on the same day.