The Versus telecast of the IndyCar race in Long Beach drew an average of 323,000 viewers during the race itself, from 4:13 to 6:30 p.m. Eastern Sunday, according to figures provided by ratings-watching website, TVbythenumbers.com.
The 2011 average audience was down 34% from the 2010 Long Beach average audience of 490,000 reported last year by IBJ.com. The household television rating for 2011 was not available. In 2010, the audience of 490,000 viewers translated into a 0.5 household rating.
Assuming every viewer was in a unique household, the highest possible household rating for an audience of 323,000 is 0.28. Nielsen Media Research estimates there are 115.9 million television households in the U.S. A "household rating" is an expression of the percentage of households tuned in to any show at a given time. Therefore, a 1.0 rating would equal an average of 1.159 million households were watching during the program.
Each household could theoretically have anywhere from 1 to 1000 people in it watching the program, so audience size does not directly translate to household ratings.