He said it's been quite a ride, and he's happy that it's been a 10-year journey that he hasn't had to travel alone.
"I don't think that ... any of us could have done it without each other, really," Gring said. "Just kind of being in the same boat from day one and completely sharing this quite unique way of growing up.
"This has been such an important part of our lives and it's kind of sculpted the kind of person I am today."
Grint's "Potter" experience has fueled his desire to stick with acting as a career.
"I do love it and I'm kind of very excited about moving on and having this kind of freedom," he said.
Grint's co-star, Matthew Lewis, who plays the final film's unlikely hero Neville Longbottom, also has no plans to change his career path.
"I want to stay in acting, I've been doing theatre for six months," Lewis said. "It's something I hated to begin with, but loved by the end of it, absolutely fell in love with it.
"Whether it's on the stage, whether it's in television, film, I just really want to carry on with this career. It's all I've known for 17 years. I think I'd be rather lost without it so hopefully I'll just be working away."