David Guetta makes a note of how much more Calvin Harris earns than him.

David Guetta at the 2017 MTV EMAs

David Guetta at the 2017 MTV EMAs

The French superstar DJ earned around $20 million less than the 'Summer' hitmaker, who was crowned Forbes' magazine's highest-paid DJ for the fifth year in a row, and says himself and his rivals all like to monitor how well their competitors are doing.

Confessing to constantly checking the magazine's annual list, 50-year-old Guetta told the Metro newspaper: "Of course, I pay attention to it.

"We all do. There is competition but in a positive way.

"We're all really good friends."

Calvin, 33, saw a significant drop from 2016's estimated $63 million earnings to $48.5 million between June

2016 and June 2017 with an impressive $48.5 million, but he still managed to come out on top.

The large sum comes from his residencies in Las Vegas, festival performances and hits like 'Feels', which he produced featuring pop megastars Katy Perry and Pharrell Williams.

Guetta, who made $25 million, has performed around 100 shows in the past 12 months around the world and owes a lot of his salary to working with Rihanna, Sia and Usher.

Commenting on his position, the 'Dirty Sexy Money' hitmaker previously said: "When I started, our music was underground.

"There was no such thing as DJ music that would be on the radio."