Super bowl is of course no match when compared to the World Cup. I think UCL final is a fair comparison to the Super Bowl, yet it still not even close. Maybe
UEFA Champions League Final vs. Super Bowl by vocativ2 - Infogram
Argentina-France World Cup Final Ratings Biggest Ever for Fox Sports
Media overstates global appeal of the Super Bowl – Human Kinetics
Super Bowl television ratings - Wikipedia
The Super Bowl: how many viewers does it have compared to the UEFA Champions League final
Super Bowl vs World Cup & Champions League: How do viewing figures for soccer & NFL showpieces compare?
Super Bowl vs World Cup & Champions League: How do viewing figures for soccer & NFL showpieces compare?
Chart: Super Bowl Pales in Comparison to the Biggest Game in Soccer