How old is the Doctor?

IMO Heaven Sent should only account for one cycle of the loop, as the Doctor who emerges onto Gallifrey for Hell Bent only experiences one loop, all the other versions of him ended when they sacrificed themselves to power up the transmat.

I'd say minus the Billions of years in Heaven Sent, if you combine all the years i'd say he's now close to 4,000 years old. I think the 8th was nearly 2,000 years old when he appeared in NOTD, then if you take the Seasons of War idea where he had some youth granted back to him and fought the time war. The War Doctor was around 800 years old in DOTD i think, so with Capaldi saying he was 2,000 before Heaven Sent. I think its, close to 4,000.

Also i actually commented on this video when it was first uploaded lol

I think Moffat has removed that question from the table, as far as specifics go. Although 11 gave his age as 1203 in S6, he also repeatedly stated later on that he has no real idea because he lost count. As noted above, we have Capaldi saying "I'm over 2,000 years old".

And then there's the problem of Heaven Sent, where he encounters the wall, goes into his mind, and remarks that he remembers "everything, every time" (ie, every time he discovers the wall). So physically he's whatever thousands of years old....but mentally, arguably billions. Or not, because perhaps he 'erases' some of that to avoid going insane and/or forgetting everything else about his life.


There's also some inconsistency if BF is all "canon"

Orbis

That, the millions of years he spent frozen in the Antarctic in, um... Frozen Time and the ridiculous number of iterations he went through in Campaign as well. There's also the Third Doctor's slip about being thousands of years old in The Silurians, but then he also claims to have known the Brigadier for "all the years" rather than the single year he's been trapped on Earth in Inferno too, so it could easily just be some trademark Pertwee bluster. There are times when I wonder whether the Doctor is measuring his total age or just the age of his present incarnation. My running pet theory until Tennant was that the nine hundred years mentioned by the Ninth Doctor was referring exclusively to his own life prior to him turning up to thwart the Auton invasion.