Over the 17 days of the games, NBC's prime-time coverage averaged 31.1 million viewers per night, up from 27.7 million in Beijing. It's the most-watched Summer Olympics since the 1996 Atlanta Olympics, and the most-watched games staged outside the United States since 1976.

NBC also says 219.4 million people watched at least six minutes of these Olympics, making it the biggest TV event since Nielsen started measuring ratings. It surpasses the 215 million who watched the 2008 Olympics.

The Peacock's adults 18-49 ratings also improved a little over the 2008 Olympics, rising from a 9.3 rating then to a 9.6 rating this year.

The women's soccer gold medal game between the United States and Japan drew the network's highest single-telecast viewership ever with 4.35 million viewers.