Last year Russell Wilson and the Seattle Seahawks won the Super Bowl. The game runs much longer than the supposed 60 minutes. Reuters

For some viewers, the Super Bowl experience can feel endless. If you’re one of those people just waiting for the big game to end, all told, it’s going to take about 3 hours and 20 minutes until the New England Patriots and Seattle Seahawks are finished playing.

The average length of the Super Bowl broadcast over the past two decades has been 3 hours and 35 minutes, according to Bloomberg in 2012. But if you excuse yourself immediately after the game, time committed should still be about 3 hours and 20 minutes.

A football game is supposed to be 60 minutes long and broken into four 15-minute quarters. So why does the Super Bowl take so much time?

A main reason for the lengthy Super Bowl experience is the halftime break that lasts about 12 to 13 minutes. Katy Perry, singer of pop hits “Roar” and “Dark Horse,” will perform this year’s halftime show. Lenny Kravitz will be feautured alongside Perry as well.

A normal football game doesn’t last anywhere close to 60 minutes, however. The game stops for a variety of reasons. There are short breaks between each quarter, which adds time. The game clock stops with two minutes remaining in the second and fourth quarters as well; this is called the two-minute warning. If a team throws an incomplete pass, meaning the ball hits the ground, the clock stops. If a ball carrier goes out of bounds, the clock stops, as well.

Each team is also allotted three timeouts per half. Those time outs stop the clock for two minutes. There are also television timeouts, to allow for commercials, either at pre-determined points in the game or during natural breaks in the play (like injuries, penalties, scoring plays, and kickoffs).

All of these stoppages of time really add up to make a football game, the Super Bowl especially, take far longer than the misleading 60 minutes.