The Doctor's age

iiiiiiAlthough The Doctor is the main charachter of Doctor Who, it is unclear what age he is. However, many little hints about his age have been given.

Timelord ageing
In the War games, the second doctor describes that a timelord cannot die of old age , so no suggestion could be described as too old. In the Doctor Who Magazine comic The Time Witch, the fourth doctor said he was a teenager for 50 years , so he must be over 50. In the episode The Stolen Earth, before he visits The Medusa cascade , he remembers visiting it when he was a kid , only nintey , so he must be older than nintey.

900 years old
Many times, The Doctor describes himself as being 900 years old. In the episode Aliens Of London, Jackie Tyler slapps the doctor for taking Rose as a companion. Later in the episode, the doctor tells Rose 900 years and I've never been slapped.