The Twelfth Doctor actor told Wales Online:
I've been asked to stay on and I haven't made my mind up about that yet, mainly because I don't want to have to make that decision. I'm trying to avoid it!Capaldi returns to our screens as the Doctor this Christmas in The Return of Doctor Mysterio, followed by twelve episodes in Series 10 next Spring. The 2017 Christmas special will be the final episode by current showrunner Steven Moffat, who will be succeeded by Chris Chibnall.
Capaldi has already appeared in 28 episodes of Doctor Who, with 13 more in production. Compare this to his predecessors, Matt Smith, who appeared in 46 episodes and David Tennant in 49. So if Capaldi did leave, he would've had a similar run. But is he ready to go?
Doctor Who does take a lot of time, but it's a wonderful use of it. It's special. I'm lucky enough to be in touch with other Doctors, and we all agree how extraordinary it is to be in this position. To decide to leave is a tough decision for everybody. [It was] very tough for Steven, so I'm just putting it off for as long as possible.
Capaldi's incarnation of our favourite Time Lord has been well received globally by new and existing fans alike. Even if this much loved Doctor does decide to leave the TARDIS with Moffat, we still have plenty of episodes to enjoy with his Doctor.