The five-time Ballon d'Or winner turns 35 in February next year, but remains a constant source of goals for Juventus and Portugal.
Ronaldo claims he will only hang up his boots once his body can longer perform the way he wants it to.
"I have never had a bad season in my life, since I am always ready to face challenges," said CR7 at the Dubai Sports Conference.
"I always play with the intention of winning. The moment my body no longer responds in the right way on the pitch, then it will be time for me to stop.
"Many years ago the ideal age to retire was 30 or 32, now you still see players aged 40."
He added: "When I quit football I would like to resume my studies. I focus a lot on studying, on learning, because unfortunately the studies I have done can't give answer all the questions I have in mind.
"One thing that fascinates me is to want to try acting in a film."