Billboard Recurrent Rules Note: Billboard radio airplay charts are compiled from a national sample of data supplied by Nielsen Broadcast Data Systems (BDS). Hot 100 Airplay is ranked by number of gross audience impressions. Mainstream Top 40, Adult Top 40, Adult Contemporary, and Modern Rock charts are ranked by total detections (aka spins).
Hot 100 / Hot 100 Airplay Songs are removed simultaneously from the Hot 100 and Hot 100 Airplay charts if they have been on the Hot 100 chart for more than 20 weeks and fall below #50.
Pop 100 Songs are removed from the Pop 100 chart if they have been on the chart for more than 20 weeks and fall below #50.
Mainstream Top 40 Descending songs are removed from the Mainstream Top 40 chart if they have been on the chart for more than 20 weeks and fall below #20.
Modern Rock Descending songs are removed from the Modern Rock chart if they have been on the chart for more than 20 weeks and fall below #20.
Adult Top 40 (HAC) Descending songs are removed from the Adult Top 40 chart if they have been on the chart for more than 20 weeks and fall below #15.
Adult Contemporary Descending songs are removed from the Adult Contemporary chart if: • • •
They have been on the chart for more than 20 weeks and fall below #15 They have been on the chart for more than 26 weeks and fall below #10 They have been on the chart for more than 52 weeks and fall below #5