<P> There are several component charts that contribute to the overall calculation of the Hot 100 . The most significant ones are: </P> <Ul> <Li> Hot 100 Airplay: (per Billboard) approximately 1,000 stations, "composed of adult contemporary, R&B, hip hop, country, rock, gospel, Latin and Christian formats, digitally monitored twenty - four hours a day, seven days a week . Charts are ranked by number of gross audience impressions, computed by cross-referencing exact times of radio airplay with Arbitron listener data ." </Li> <Li> Hot Singles Sales: (per Billboard) "the top selling singles compiled from a national sample of retail store, mass merchant and internet sales reports collected, compiled, and provided by Nielsen SoundScan ." The chart is released weekly and measures sales of physical commercial singles . With the decline in sales of physical singles in the US, many songs that become number one on this chart often do not even chart on the Hot 100 . </Li> <Li> Hot Digital Songs: Digital sales are tracked by Nielsen SoundScan and are included as part of a title's sales points . </Li> <Li> Streaming Songs: a collaboration between Billboard, Nielsen SoundScan and National Association of Recording Merchandisers which measures the top streamed radio songs, on - demand songs and videos on leading online music services . </Li> </Ul> <Li> Hot 100 Airplay: (per Billboard) approximately 1,000 stations, "composed of adult contemporary, R&B, hip hop, country, rock, gospel, Latin and Christian formats, digitally monitored twenty - four hours a day, seven days a week . Charts are ranked by number of gross audience impressions, computed by cross-referencing exact times of radio airplay with Arbitron listener data ." </Li> <Li> Hot Singles Sales: (per Billboard) "the top selling singles compiled from a national sample of retail store, mass merchant and internet sales reports collected, compiled, and provided by Nielsen SoundScan ." The chart is released weekly and measures sales of physical commercial singles . With the decline in sales of physical singles in the US, many songs that become number one on this chart often do not even chart on the Hot 100 . </Li>

Who has the number one song this week