The Doctor ' s age Contradictory information has pointed at different estimates of the Doctor ' s age , both in conversations and in terms of the length of various incarnations . Statements and information . It was difficult to determine the Doctor ' s life expectancy , given his ability to regenerate . The Second Doctor once stated that as a Time Lord he could " live forever , barring accidents " . ( TV : " The War Games " ) A Time Lord named Handrel claimed that a single incarnation of a Time Lord could live for around ten thousand years . ( PROSE : " The Time Lord ' s Story " ) It was also evident that Time Lords aged in a way different from human s . The Fourth Doctor once told his companion that he was a teenager for fifty years . ( COMIC : " Doctor Who and the Time Witch " ) He also went through spans of linear time longer than average human lifespans without growing visibly older . ( PROSE : " Escape Velocity " , AUDIO : " Orbis " , TV : " The Impossible Astronaut " ) Cindy Wu pointed out the uncertainty in whether the Doctor gave his age in Gallifreyan or human year s , " or some cosmic measurement tied to absolute zero universal center ? " ( COMIC : " The Lost Dimension " ) By the Doctor ' s eleventh incarnation , " he had long since abandoned trying to keep track of [ his age ] in any way that mattered to anybody but him . " ( PROSE : " Nothing O ' Clock " ) First Doctor . The First Doctor was eight when he entered the Academy , along with the Master . ( TV : " The Sound of Drums " ) He apparently left primary school at the age of 45 . ( PROSE : " Shroud of Sorrow " ) He later described himself as having been " just a kid " when he first visited the Medusa Cascade , at the age of 90 . ( TV : " The Stolen Earth " ) He said he was a " teenager " for fifty years . ( COMIC : " The Time Witch " ) When the Fourth Doctor was 759 , ( TV : " The Ribos Operation " ) Romana noted the Doctor had been travelling in the TARDIS for 523 years . This would have made the Doctor about 236 when he first " borrowed " the TARDIS and left Gallifrey . ( TV : " The Pirate Planet " ) This figure was broadly supported by the TARDIS itself . When transferred into a humanoid body , the TARDIS said the Doctor had travelled with it for 700 years . At this point , the Eleventh Doctor was around 909 years old , putting his age when he stole the TARDIS at 209 . ( TV : " The Impossible Astronaut " , " The Doctor ' s Wife " ) During the time Susan Foreman travelled with the Doctor , Ian Chesterton , and Barbara Wright , she knew that despite his apparent maturity , in terms of their own species the Doctor was considered an adolescent . ( AUDIO : " Here There Be Monsters " ) He stated he had been travelling in the TARDIS for 60 years when he visited 64 , putting his age at 296 . ( PROSE : " Byzantium ! " ) The Doctor spent " centuries " studying at the Time Lord Academy . ( COMIC : " Mortal Beloved " ) Magnus chided the Doctor for not regenerating and for holding on to this incarnation as long as he did . ( COMIC : " Flashback " ) To the best of his memory , the Doctor recalled having met Bill Cody just before his 400th birthday . ( COMIC : " Gaze of the Medusa " ) This incarnation regenerated when he was 450 - years - old , ( PROSE : " Iceberg " ) roughly 1 , 500 years before his fourteenth regeneration . ( TV : " Twice Upon a Time " ) Second Doctor . The Second Doctor told Victoria Waterfield he was " something like " 450 years old in Earth terms . ( TV : " The Tomb of the Cybermen " ) However , he also made claims saying he was several thousand years old , but gave no specific age . He gave his age as a " tender " 500 shortly before his regeneration . ( COMIC : " The Brotherhood " ) Third Doctor . The Third Doctor told Liz Shaw that his life covered " several thousand years " . ( TV : " Doctor Who and the Silurians " ) He started to say to Professor Kettering that he had been a scientist for " several thousand " years , but stopped himself before completing the sentence . ( TV : " The Mind of Evil " ) Fourth Doctor . The Fourth Doctor gave his age as 748 shortly after he had first regenerated , ( PROSE : " A Device of Death " ) and later on he consistently said he was " something about 750 " , about 757 or 749 when he travelled with Sarah Jane Smith ( TV : " Pyramids of Mars " , " The Android Invasion " , " The Brain of Morbius " , " The Seeds of Doom " ) , a further year older ; 750 when travelling with Leela ( TV : " The Robots of Death " ) and 756 with Romana during her first incarnation just before finding the first segment of the Key to Time . Romana corrected him , saying he was 759 . ( TV : " The Ribos Operation " ) Before they assembled the Key to Time , he turned 760 ( TV : " The Power of Kroll " ) and he was still attributed that age while fighting Skagra . ( PROSE : " Shada " ) When he met Sharon Davies , the Doctor claimed to be 730 years old , and blamed his age for his faulty memory . ( COMIC : " Doctor Who and the Star Beast " ) Another time while travelling with Sharon , after ageing four years due to the chrono - compensator , he decided he would still think himself as " 743 . . . or was it 730 , I never can remember " . ( COMIC : " Doctor Who and the Time Witch " ) He claimed at various times to be anything from 400 to a shade over 1000 years old . ( PROSE : " Evolution " ) Romana told the Doctor that after the first couple hundred years , it would be hard to remember his exact age . Fifth Doctor . The Doctor said he was 813 when he regenerated into his fifth incarnation . ( PROSE : " Cold Fusion " ) Later in his life , he stated that he was " pushing 900 . " ( AUDIO : " Omega " ) While travelling with Erimem and Peri Brown , the Doctor claimed to be " not even middle - aged by [ Time Lord ] standards . " ( AUDIO : " No Place Like Home " ) Sixth Doctor . The Sixth Doctor said he was 900 years old while travelling with Peri . ( TV : " Revelation of the Daleks " , " The Mysterious Planet " ) , " not a day over nine hundred years old " when threatened with death by stoning . ( PROSE : " The Mysterious Planet " ) While travelling with Flip Jackson , he spent a century frozen in Vortex Ice . ( AUDIO : " Vortex Ice " ) Flip later called him around 900 , but she was not sure on the exact age . ( AUDIO : " The Middle " ) The Doctor told his companion Constance Clarke that he was over 900 years old . ( AUDIO : " Absolute Power " ) By the time he was travelling with Melanie Bush , he had blown out the candles on his 900th birthday cake . ( AUDIO : " The One Doctor " ) The Malamud noted that , because of the many volumes about the Doctor ' s life , he must be 20 , 000 years old . The Doctor didn ' t contradict them . ( PROSE : " The Book of My Life " ) At another time , he was 991 during his travels with Melanie Bush . ( PROSE : " A Wee Deoch an . . . ? " ) He was 953 years old when he regenerated . ( TV : " Time and the Rani " ) Seventh Doctor . Hours after his regeneration , the Seventh Doctor unlocked a door in the Rani ' s laboratory with the numerical code " 953 " , saying it was both his age and the Rani ' s . ( TV : " Time and the Rani " ) The Doctor had his 1 , 000th birthday while travelling with Ace and Bernice Summerfield . ( PROSE : " Set Piece " ) On arriving in the Forge , the Seventh Doctor claimed that " a century or three " had passed in his personal timeline since his previous incarnation visited it . ( AUDIO : " Project : Lazarus " ) By his own estimate afterward he would have been 1009 when he regenerated , though he admitted he may have lost count at some point . ( PROSE : " Vampire Science " ) Eighth Doctor . Three years after his regeneration , the Eighth Doctor calculated his total age to be 1012 . He was unsure and might have lost count , and so preferred to simply begin counting at his most recent regeneration , giving his age as " three " when asked . ( PROSE : " Vampire Science " ) The Doctor later stated his age as 1018 . ( PROSE : " Autumn Mist " ) The Doctor aged while trapped as an amnesiac on Earth in " real time " between the late 19th century ( PROSE : " The Ancestor Cell " ) and the year 2001 , making him at least 1125 by the end of this crisis . ( PROSE : " Escape Velocity " ) While travelling with Charley Pollard , the Doctor said he was " nine hundred and fifty something years old " . ( AUDIO : " Neverland " ) Not long after , while travelling in the Divergent Universe , he was noted to have had " over a thousand years worth of collected experience " by a cave creature in the form of Major Koth . ( AUDIO : " The Twilight Kingdom " ) While travelling with Lucie Miller , the Doctor spent 600 years on the planet Orbis . He later mentioned that he rounded and adjusted his age based on different year lengths in different parts of the universe , claiming that in one obscure galaxy he would be two years old . ( AUDIO : " Orbis " ) The Doctor spent several months travelling with Nyssa on board " The Traken " during the Last Great Time War . ( AUDIO : " A Heart on Both Sides " ) War Doctor . The Last Great Time War , in which the War Doctor fought , lasted not less than 400 years of linear time , although at the time of his experiences in the Tantalus Spiral , which led him to decide the war could go on " no more " , this incarnation ' s age was a hundred years or more . ( PROSE : " Engines of War " ) Shortly before the end of his life , the War Doctor said he was 400 years younger than the Eleventh Doctor when he gave his age as " twelve hundred or something " , making him somewhere between 800 and 900 years old . ( TV : " The Day of the Doctor " ) Ninth Doctor . The Ninth Doctor claimed " 900 years of time and space " . Immediately after he made this comment , he told Rose Tyler it was " [ his ] age . " ( TV : " Aliens of London " ) Even after he spent 28 years waiting on Earth to met up with Rose in 1922 , ( AUDIO : " The Other Side " ) he still considered himself to have had " 900 years of phone box travel " . ( TV : " The Empty Child " ) Tenth Doctor . The Tenth Doctor said he was 903 years old while attempting to rescue the " Titanic " . ( TV : " Voyage of the Damned " ) Prior to the " Titanic " incident , he claimed to have spent at least 33 months searching for Martha Jones in deep space ( TV : " The Infinite Quest " ) , and several months living in various time periods on Earth ( PROSE : " The Stone Rose " , TV : " Human Nature " / " The Family of Blood " , " Blink " ) and inside the " Valiant " during the so - called Year That Never Was . ( TV : " Last of the Time Lords " ) He again claimed 903 during an adventure with Donna Noble . ( AUDIO : " The Nemonite Invasion " ) In a later adventure in Nevada , he said 900 again , suggesting he was approximating . ( TV : " Dreamland " ) While confronting a rabbit in Elizabethan England he briefly believed to be a Zygon in disguise , he said he was 904 years old . ( TV : " The Day of the Doctor " ) Just prior to regenerating , he gave his age as 906 , suggesting that several years had passed for the Doctor after his travels with Donna Noble . ( TV : " The End of Time " ) However , during an adventure with Donna Noble on the planet Calibris , the Doctor shot himself with several time reaver gun s . While ten minutes passed for those around him , he spent 7 centuries frozen in time . ( AUDIO : " Time Reaver " ) Also , when the Doctor was imprisoned on Volag - Noc , his brain was scanned for criminal activity , revealing that some of his memories dated back over 3000 years . ( TV : " The Infinite Quest " ) Eleventh Doctor . Not long after Amy Pond first encountered the Eleventh Doctor , he told her that he was 907 . ( TV : " Flesh and Stone " ) During his travels with Alice Obiefune , the Doctor claimed to have lived " 900 - odd - years . " ( COMIC : " Pull to Open " ) When his future self invited him to Utah , the younger Doctor gave his age as 909 . ( TV : " The Impossible Astronaut " ) The Doctor later commented that he was around George ' s age of eight " about a thousand years ago " . ( TV : " Night Terrors " ) When he met Amy , Rory , River and Canton at Lake Silencio , his older self told Amy that he was 1103 . ( TV : " The Impossible Astronaut " ) Indeed , the Doctor at this point in his life had just finished his farewell tour , which appeared to have lasted about 200 years . ( TV : " The Wedding of River Song " ) By the time he had left Amy and Rory , but still offered them brief trips in the TARDIS , he stated his age as 1200 . ( TV : " A Town Called Mercy " ) When asked if he knew any tricks , the Doctor stated that he ' d been escaping for " about a thousand years , give or take a century or so . " ( PROSE : " Magic of the Angels " ) When he met Clara Oswald , he rounded his age down to 1000 . ( TV : " The Bells of Saint John " ) The Doctor later spent three years trapped in a vast room within the TARDIS . ( COMIC : " Sky Jacks " ) When asked by the War Doctor , he said he didn ' t know and had lost track , settling on " 1200 - and - something " . He went on to say that he was so old he couldn ' t remember if he was lying about his age . ( TV : " The Day of the Doctor " ) During the Siege of Trenzalore , the Doctor told Theol that he was " nearly " 1500 , but he could be a few hundred years off either way . ( PROSE : " An Apple a Day . . . " ) By the time Clara saw him next , he had spent 300 years defending the world of Trenzalore , making him at least 1500 years old . . ( TV : " The Time of the Doctor " ) By the time the Mara began attacking the residents of Trenzalore , the Doctor had been there for 750 years , making him 1950 . ( PROSE : " The Dreaming " ) In total , the Doctor spent 900 years on Trenzalore , making him roughly 2100 years old at the end of his first complete cycle of regenerations . ( PROSE : " " ) Twelfth Doctor . Shortly after his regeneration , the Twelfth Doctor claimed to have lived for over 2000 years . ( TV : " Deep Breath " ) He possessed a Two Thousand Year Diary which he used to identify the Mire . ( TV : " The Girl Who Died " ) The Doctor hid for 139 years in a stasis chamber in order to maintain his personal timeline . ( TV : " Under the Lake " , " Before the Flood " ) As a result of a Time Lord plot , the Doctor spent around 4 . 5 billion years ( TV : " Hell Bent " ) trapped in a confession dial , and , although it was divided amongst countless copies of the Doctor , he implied that he retained those memories upon escaping . ( TV : " Heaven Sent " ) The Doctor would admit to Osgood that he had lost track of his age . ( COMIC : " Robo Rampage " ) Whilst travelling alone , told the Doctor he was " getting old " , having lived for centuries . ( PROSE : " Dr . Twelfth " ) After this , the Doctor told a much younger incarnation of the Master that he was age 4 billion . ( COMIC : " Doorway to Hell " ) At some point afterwards , the Doctor spent a twenty - four year night on Darillium with River Song . ( TV : " The Husbands of River Song " ) " A long time ago " , the Doctor made an oath to guard the body of Missy for 1000 years . After this he transported her to the Vault beneath St Luke ' s University . ( TV : " Extremis " ) In late 2016 , he had apparently been lecturing at the university for over fifty years , although some rumours said he had been there for over seventy . ( TV : " The Pilot " ) Before his first adventure together with Bill Potts , the Doctor told Nardole that he was over 2000 years old . ( TV : " Smile " ) A few hours after this , he echoed the same thing to Bill herself . ( TV : " Thin Ice " ) On meeting the Monks in a simulation , the Doctor gave his age as " two thousand years at the last count " . ( TV : " Extremis " ) Shortly before regenerating , the Twelfth Doctor , in an encounter with his first incarnation just prior to his own regeneration , commented that 1500 years of " rock ' n ' roll " had passed in the interim . ( TV : " Twice Upon a Time " ) Thirteenth Doctor . Immediately following regeneration , the Thirteenth Doctor was at least 1500 years older than the Second Doctor , making her a minimum of 1950 years old . ( PROSE : " Iceberg " , TV : " Twice Upon a Time " ) Behind the scenes . The " 900 " discrepancy . Before the Eleventh Doctor ' s 200 - year farewell tour between TV : " The God Complex " and " Closing Time " , the writers of the 2005 revival of the series explicitly described the Doctor as around 900 years old , despite contrary statements on TV and expanded media . It is one of the few notable contradictions of previously established material in the revival . To date no episode , novel or comic strip has addressed the discrepancy directly . " He has no clue " . A simple and self - evident theory is that the Doctor doesn ' t know how old he is because he has lost count , constantly travelling backward and forward through time making it difficult to measure one ' s lifespan at all . This theory began as fanon , with the Doctor occasionally admitting to being unsure of his age in spinoff media . ( COMIC : " Doctor Who and the Time Witch " , PROSE : " Vampire Science " ) This is the theory subscribed to by " Doctor Who " executive producer and head writer Steven Moffat in an interview with SFX : This theory would be voiced in " The Day of the Doctor " , written by Steven Moffat , when the Eleventh Doctor is asked by the War Doctor how old he is now . Non - fictional sources . The first non - fictional writing about regeneration , " The Phoenix in the TARDIS " , stated that the First Doctor was about 900 at the time he regenerated into the Second Doctor .