The United World Chart is a worldwide chart issued every week by Media Traffic, using both sales (digital and physical) and airplay to determine the most popular albums and singles worldwide. The United World Chart uses the same system as the Billboard Hot 100, in which the tracking-week for sales begins on Monday and ends on Sunday; meanwhile the airplay tracking-week runs from Wednesday to Tuesday. The newest weekly chart is therefore issued every Thursday. Each chart is dated with the "week-ending" date of the following Saturday. ::Monday, January 1 – sales tracking-week begins ::Sunday, January 7 – sales tracking-week ends ::Thursday, January 11 – new chart released, with issue date of Saturday, January 20.
In March 2007, Media Traffic ranked "Candle in the Wind 1997" as the most successful song in the chart's history.
Starting in 1999, the first song to reach number one was "Believe" by Cher. As of June 16, 2007, the United World Chart has had 108 number one hits.
Media Traffic began displaying charts that traced back to 10, 20, 30, 40 and 50 years ago.
