The English and Italian champions go head-to-head in the last 16 of Europe's elite competition, with the first leg in the Giuseppe Meazza on 24th February before the return tie at Old Trafford on 11th March.
But Ronaldo believes, while Inter are good, the reigning European champions should have too much in the locker for the Italian side.
He told Rai Sport: "Inter are a good team with great players but we're better than them and I'm sure we'll beat them.
One step"If we beat them we'll feel like we're just one step away from the final."
The ties see Ronaldo renew rivalry with Inter boss and fellow Portuguese Jose Mourinho, with whom he once had a spat during the coach's time at Chelsea.
Ronaldo had claimed that Mourinho needed to take responsibility for Chelsea's defeats rather than complaining about referees while Mourinho responded that Ronaldo was immature and lacked respect, possibly due to a troubled childhood.
Since then, Ronaldo has lifted the World Player of the Year award but Mourinho stated his striker Zlatan Ibrahimovic is better.
Trophies"I respect everyone's opinions but the trophies that count are in my home," said Ronaldo, who went on to criticise Mourinho's treatment of compatriot Ricardo Quaresma, who moved on loan to Chelsea this week after finding his opportunities limited at Inter following a big-money summer move.
"Ricardo has some great qualities and it's a shame that he wasn't given the time to prove his true worth," he said.
"He was great for Porto and Portugal and he can't be judged on a few matches where he hasn't been at his best.
"Probably the fact that he was transferred for such a large sum of money put too much pressure on him and in Italy it's not easy to do well straight away."