According to UEFA rankings for club competitions, these are the 20 best clubs in European football.
The results are based on points gained by clubs that have competed in the Champions League and Europa League over the past five seasons.
As stated on UEFA's website, the points system work as follows:
UEFA Champions League
First qualifying round elimination – 0.5 points
Second qualifying round elimination – 1 point
Group stage participation – 4 points
Group stage win – 2 points
Group stage draw – 1 point
Round of 16 participation – 4 points
UEFA Europa League
First qualifying round elimination – 0.25 points
Second qualifying round elimination – 0.5 points
Third qualifying round elimination – 1 point
Play-off elimination – 1.5 points
Group stage win – 2 points