Ancelotti, 50, hopes to boss the Blues until he is at least 70.
He said: "10 years? Why not 20? My objective is to stay here a long time. I can do this if I do a good job and if the club is happy."
"I'm a young coach. I am an Italian coach. For an Italian coach, it's very difficult to think about staying at one club more than five years.
"Up to now, the club is happy with the job I've done I think. I want to continue and improve.
"I stayed at Milan for eight years and, for an Italian coach, that was a record. In England, it's easier to stay at a club for a long time."