A regulation game of American football in the National Football League (NFL) has four 15-minute quarters. If you are watching a game from start to finish, it will take approximately three hours. According to recent studies, the ball is in play on the field for just eleven minutes in an average football game. A single play lasts for about four seconds, though the clock continues to run even when a play is over. In a football broadcast, fans spend most of the time watching replays, commentary, pre-recorded video footage, and commercials.