How do you convert a Nielsen rating into the number of viewers?

October 28, 2014 1:33 PM

According to Wiki, "A single national ratings point represents one percent of the total number, or 1,156,000 households." But that doesn't jibe with the numbers coming from the World Series: "Kansas City's 3-2 win in Game 3 received a 7.2 rating and 12.1 million viewers, according to fast national ratings from Nielsen Media Research announced by Fox on Saturday." What I'm really trying to figure out is how many viewers make up a 0.86 rating?
posted by wensink to Sports, Hobbies, & Recreation (3 answers total)

With the 7.2 rating, Nielsen is saying that about 8.3 million households watched the game. Presumably many households have more than one person watching the game. In this case, it appears that Nielsen is assuming that there are, on average, a little less than 1.5 viewing the game in each household.
posted by indyz at 2:59 PM on October 28, 2014

Response by poster: But how are they getting at that number from the rating?

To illustrate, can you solve this:
How many viewers are watching a program that receives a 0.86 rating?
posted by wensink at 3:57 PM on October 28, 2014

I've been digging into this more since I posted my answer, and it is confusing. These are the current Nielsen demographic estimates. It appears that the 7.2 rating is for the Households demographic. I've also seen 3.1, which is the rating for the Adults 18-49 demographic. According to this, the 12.1 million viewers number is based on the People 2+ demo. From there, working backwards off of the demographic data implies that the People 2+ rating must be 4.1.

It seems like most sources publish the Households number when they talk about "ratings" without qualification. The 18-49 numbers are also readily available. For whatever reason, instead of listing the People 2+ rating, they do the math and convert it to total viewers.

To answer your question: If the 0.86 rating is for Adult 18-49 or Households, you can't. If 0.86 is the rating for the People 2+ demographic, multiply by 2.9456 million.
posted by indyz at 5:04 PM on October 28, 2014