I got curious and did some quick searching. Looks like it depends greatly on the content and network with dramas usually having shorter breaks than sitcoms. The Big Bang Theory for instance averaged 17 minutes apparently.
One interesting factoid I found was that The Wizard of Oz, which is 101 minutes long, took up a 120 minute block in the 60s unedited but a 180 minute block today with edits to make it shorter.
I got curious and did some quick searching. Looks like it depends greatly on the content and network with dramas usually having shorter breaks than sitcoms. The Big Bang Theory for instance averaged 17 minutes apparently.
One interesting factoid I found was that The Wizard of Oz, which is 101 minutes long, took up a 120 minute block in the 60s unedited but a 180 minute block today with edits to make it shorter.