Age Age was the length of time that a person lived or a thing existed , or had been alive . Different species could live out lifespan s of various lengths , and reach different ages . Rose Tyler was said to be have been 19 on a poster when she left Earth with the Ninth Doctor and didn ' t return for a whole year . ( TV : " Aliens of London " ) Arriving in the year 2012 , Rose noted that she would be 26 by this time . ( TV : " Dalek " ) Jackie Tyler celebrated her 40th birthday in February 2007 . ( TV : " Rise of the Cybermen " ) Later that year , she insisted that she was 40 when the Tenth Doctor , attempting to pass her off as Rose to Yvonne Hartman , claimed that she had aged 57 years as a result of looking into the time vortex . ( TV : " Army of Ghosts " ) Owen Harper died for the first time at only 27 years old . ( TV : " Dead Man Walking " ) Reversing age . Seeking to escape the Last Great Time War , travelled to the far future where he used a Chameleon Arch to transform into a human baby which was left on the Silver Devastation . ( AUDIO : " The Heavenly Paradigm " , TV : " Utopia " ) Looking into the heart of the TARDIS , Blon Fel - Fotch Passameer - Day Slitheen was regressed to an egg , which the Ninth Doctor took to Raxacoricofallapatorian to give her a second chance at life . ( TV : " Boom Town " ) Through his invention of a hypersonic soundwave manipulator , 76 year old Richard Lazarus reversed his physical age , but the process resulted in dormant genes awakening and transforming him into a monster . ( TV : " The Lazarus Experiment " ) Suspending age . In Pete ' s World , John Lumic invented the Cybermen , created through the conversion of human s to a metal " body that [ would ] never age or die " . ( TV : " Rise of the Cybermen " ) Having been preserved as a face in a pavement slab by the Tenth Doctor , Ursula Blake noted that she would never age . ( TV : " Love & Monsters " ) After being brought back to life in an undead state with the resurrection gauntlet , Owen Harper stopped aging . ( TV : " Dead Man Walking " ) Accelerating age . Through use of technology from the Hypersonic soundwave manipulator incorporated into his laser screwdriver alongside a sample of the Tenth Doctor ' s biological code from his severed hand , accelerated his physical age by " a hundred years " . ( TV : " The Sound of Drums " ) A year later , the Master further aged the Doctor . Regeneration capacity suspended and his true age of 900 brought to the surface , the Doctor was reduced him to a small and wizened creature . ( TV : " Last of the Time Lords " ) Martha Jones ' physical age was accelerated to her 80s when she was attacked by a resurrection gauntlet . The process was reversed when Duroc was defeated by Owen Harper . ( TV : " Dead Man Walking " ) The Doctor ' s age . The Doctor ' s age was widely inconsistent . The First Doctor was said to be 450 years old when he regenerated into the Second Doctor . ( PROSE : " Iceberg " ) The Seventh Doctor claimed to be 953 years old soon after regenerating , the same age as the Rani , ( TV : " Time and the Rani " ) yet by the time of his war incarnation , he claimed to be 400 years younger than his eleventh incarnation , who said he was " 1200 and something " . ( TV : " The Day of the Doctor " ) The Ninth Doctor claimed to be 900 ( TV : " Aliens of London " ) , with the Tenth Doctor , Eleventh Doctor and Twelfth Doctor all following on from that . The Tenth Doctor claimed that he was 903 , 904 and then 906 . ( TV : " Voyage of the Damned " , " The Day of the Doctor " , " The End of Time " ) The Eleventh Doctor claimed that he was 907 a few days after regenerating , then 909 , 1103 and then 1200 . ( TV : " Flesh and Stone " , " The Impossible Astronaut " , " The Wedding of River Song " , " A Town Called Mercy " ) The Twelfth Doctor claimed to be around 2000 on numerous occasions , ( TV : " Deep Breath " , " Smile " , " Extremis " ) and roughly 1500 years older than his original incarnation . ( TV : " Twice Upon a Time " ) Through his Time Lord ability to regenerate , the Doctor ' s true age was not reflected in his physical appearance . ( TV : " Last of the Time Lords " )