Manchester United and Real Madrid have sold more shirts than any other football club in the last five years.
Figures show that both clubs have sold an average of 1.4m shirts in that time period, with United kits made by Nike and the Spanish champions' donning the Adidas brand.
Barcelona have entered the list in third place with average sales of 1.15m a year, while Champions League winners Chelsea sit in fourth with sales of 910,000.
English clubs Liverpool and Arsenal also made the top 10 along with Italian outfits AC Milan, Juventus and Inter Milan.