Ronaldo, who won a second Ballon d'Or in January, has started the season in blistering fashion, plundering 17 goals in 11 games for the European champions.
"I know what it means to play in a team with great individual quality," Kroos, a World Cup winner with Germany, told Die Welt. "We all respect each other, the spirit is amazing.
"At the moment, there is no better player than Cristiano. He was one of those who looked out for me at first, he's a really nice guy.
"I was lucky to come from a club with great standards. In Munich, it's more than stepping out on to the field to win - you start the season to win titles. So I didn't have to adapt a lot.
"I enjoy playing in Madrid. Although people may not believe me, it's a family club. I feel that people trust me."
Kroos penned a six-year deal with Los Blancos in July from Bayern Munich.