Do we have any idea how big the interior of the TARDIS is?

Is it even a fixed size, since it was recently renewed?

  • 27
    It is as big as it needs to be.
    – Xantec
    Commented Dec 8, 2011 at 18:38
  • 19
    @Xantec: The Doctor likes to be prepared. It's slightly bigger than it needs to be :-)
    – Jeff
    Commented Dec 9, 2011 at 14:15
  • 6
    Precisely one "plot" large.
    – Valorum
    Commented Oct 27, 2014 at 23:46
  • 1
    @user14111 Cubic? The TARDIS isn't a cube...
    – user11521
    Commented Apr 8, 2016 at 16:31
  • 2
    @Michael No, but volume is still measured in cubic units. Cubic centimeters, cubic inches, cubic miles, cubic light-years. However, the acre is a measurement of surface area (a unit of land area equal to 4,840 square yards) so cubic acres isn't something you would really do. Commented Jun 7, 2016 at 22:49

13 Answers 13


Short version: No, all we know is that it's bigger on the inside.

Long version: The exact size, shape, and layout of the TARDIS has never been fully described, and the layout can change depending on season, and the writer. The only fixed room in the TARDIS is the main control room (the room with the central console that is seen in almost every episode). Even that room changes, usually getting a new layout, or slight improvements when there's a new Doctor (occasionally changing mid-Doctor, though).

There are a few other "known" rooms, including a Library, Wardrobe, Cloister Room/Bell (the Cloister Bell sounds when danger is imminent), a Holding Ring (which is where rooms of past companions could be found), and a Swimming Pool. (Source). Additionally, there's various storage rooms, and it's implied that each companion, upon joining the Doctor in his travels, gets a room to store all their stuff. There's also rooms that store food, a few bathrooms, lots of corridors, medical bays, and feasibly any number of other rooms used for any number of other purposes.

Additionally, there is at least one secondary control room used for a period of time by the Fourth Doctor. In The Doctor's Wife, the TARDIS mentions that it has "archived thirty control rooms", only 12 of them had happened yet. More details on the different control rooms can be found here: TARDIS Control Rooms

  • 8
    I believe there was a passing reference to "squash court number eight". Commented Dec 9, 2011 at 15:50
  • 3
    How does Community (a bot) know about Doctor Who? It's changed the text here... Commented Aug 9, 2012 at 9:32
  • 3
    @Wikis Given that it changed the text wrongly (the original text was correct), perhaps it doesn't know about Doctor Who.
    – Mr Lister
    Commented Aug 9, 2012 at 20:30
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    I distinctly remember an episode with, I believe, Peter Davison as the Doctor, where there was some sort of emergency and the Doctor had to jettison rooms. The big plot tension point was that the rooms would be chosen randomly so there was a risk that the control room would be one of the jettisoned rooms, but of course that didn't happen (the main characters never die!). I do remember him claiming that there were an infinite number of rooms, and it bothered me.
    – steveha
    Commented Feb 21, 2014 at 23:34
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    @steveha - the episode is Castrovalva part 1 (Season 19 episode 1). The episode actually gives some vague kind of indication of the scale of the TARDIS, at least in some way -- the mass of the jettisoned rooms is converted to thrust (via some unknown mechanism of unknown efficiency), and is specified that "17,000 tons" would be enough, and that this is "say 25%" of the mass of the TARDIS's "architecture".
    – Jules
    Commented Apr 8, 2016 at 12:55

The only hard fact we have about the interior of the TARDIS is "Bigger than the outside."

It's been said several times that the Doctor can control the configuration of the TARDIS interior, and he has in fact changed it several times ("You've changed the desktop theme" from the 10th Doctor's Children in Need special).

The inside of the TARDIS has no real effective limit - we've seen tiny containers with space for millions of Daleks in the new series, and we know that (this being Doctor Who) anything that's stated is subject to future retcon.


I'm not sure how accurate or serious was the Doctor, but in Journey to the centre of the TARDIS, the Doctor states it is infinite:

-Picture the biggest ship you've ever seen. Are you picturing it?


-Good. Now forget it. 'Cause this ship is infinite.

The Doctor always lies, but I don't see a reason why the Doctor would want to lie about that.

  • 2
    Remember Rule #1, though. The Doctor lies. Commented Apr 28, 2013 at 21:33
  • 1
    @AvnerShahar-Kashtan: I hate when people remind me that. It basically destroys any evidence coming from the Doctor's mouth XD!! There, I did a small edit.
    – Saturn
    Commented Apr 28, 2013 at 21:34
  • Not everything he says, of course, but only every time he seems to make grand, sweeping generalities or solid truths. Those are the times he lies. :) Commented Apr 28, 2013 at 21:36
  • To paraphrase a certain Cardassian spy, "Quite often a lie is the most potent truth."
    – Jeff
    Commented Jul 12, 2016 at 13:24
  • If it is infinite then there is no reason to delete rooms for more power and it wouldn't need the Eye as a power source,.sounds like he just meant bigger than you could imagine when he said that
    – Matt
    Commented Sep 2, 2020 at 21:35

In a discussion at the Permuted Press forums, Peter Clines said:

"The War TARDIS idea gets a lot of use in the books that revolved around the Time War (well... around the original Time War), like The Ancestor Cell. One of the funny bits is that War TARDISes appear as massive, planet-sized battleships. The Doctor's companions are terrified, but he brushes it off by explaining the Time Lords are just showing off and using the chameleon circuits to make the outside of each TARDIS match the inside."

I've yet to read that novel, but as it's an Eighth Doctor adventure, its canonicity is in question.


Well, the Doctor once had to jettison a quarter of it (the TARDIS). It was infinitely large, which caused a bit of cognitive dissonance for Adric. ("Castrovalva", 19th season, first serial, January 1982) That the jettisoned portion contained the Zero Room caused quite a bit of physical dissonance for the Doctor. (Then, bizarrely: Carpentry to the rescue!)

  • 2
    Are you sure about the infinitely large bit? I've just scanned the transcripts here from Castrovalva to Earthshock, and none of them contain the word "infinite"...
    – Jules
    Commented Apr 8, 2016 at 13:19
  • @Jules : Then Adric objecting that one can't eject a quarter of an infinite quantity must be from the other time they attempted this maneuver -- to escape from E-space. I don't have access to transcripts currently. Commented Apr 8, 2016 at 18:14

In the episode Journey to the Centre of the TARDIS, don't forget that the Eye of Harmony, or the main power source for the TARDIS is literally a decaying star sitting in what I can only describe as a Dyson sphere.

Big? Big isn't the word for it. Fracture the surface of the Earth? I'd say closer to crushing it and terminating every speck of life on it.

  • 1
    I'm not seeing how this answers the question...
    – Mithical
    Commented Feb 2, 2017 at 9:40
  • @Mithrandir - I believe he his saying the TARDIS must be at least big enough to contain a star, or maybe a Dyson sphere. Commented Feb 2, 2017 at 11:20

According to the 1983 Doctor Who Technical Manual, the TARDIS interior is infinite in size. However, this would seem to be contradicted by statements in the show, including ones from the same era. The most notable problem would be with the decision in jettison one quarter of the TARDIS in "Castrovalva," which does not really make sense if the ship is actually infinite.

I asked Peter Davison about this at a Doctor Who convention, and he said that, as far as he was concerned, the TARDIS was very large, but finite in size. "Big, big," was the way I think he phrased it. He blew off whatever the Technical Manual said as irrelevant cruft. Although I doubt Davison had ever looked at the book, dismissing it was probably not a terrible idea, since it contained some other obvious howlers—like placing the kaled mutant at the very bottom of the dalek interior it showed.

  • I remember one episode where some invaders (Daleks maybe?) had got into the TARDIS and the Doctor, Tom Baker, was on the run inside it. He was running down a very long brick corridor on 'The Factory Levels' and that was one of the first reveals as to just how big the blue box is
    – Danny Mc G
    Commented Jul 6, 2019 at 9:22
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    @DannyMcG That's "The Invasion of Time," with the Sontarans loose in the TARDIS. They filmed it in a disused hospital.
    – Buzz
    Commented Jul 6, 2019 at 14:53
  • It's not illogical to have a quarter of infinity. There are infinite real values between zero and 1. Yet we can remove a quarter of them by removing all the values between 0 and 0.25. Commented Oct 27, 2021 at 20:46
  • @DJClayworth That is only true because the finite interval [0,1] has a finite Lebesgue measure. A structure that is unbounded in space (like a TARDIS interior in which one can continue to travel forever) does not have that property.
    – Buzz
    Commented Oct 28, 2021 at 0:05
  • Where did you get the idea that the Tardis interior was unbounded in space? Or that you could travel within it forever (except in the obvious case of going up and down the same corridor for an infinite amount of time - which presumably is what Tom Baker did thanks to BBC budget restrictions). Commented Oct 28, 2021 at 0:24

Maybe the Tardis is a procedurally generated world just like content is created in some computer games, where new rooms are automatically created as they are needed or discovered. Effectively making it potentially infinite.

  • Welcome to the site. We prefer answers that are grounded in some sort of evidence. Do you have a source for this answer or is it just speculation?
    – amflare
    Commented Jan 15, 2018 at 16:05

Well the doctor does state that it's the biggest ship in the universe, and if you're keeping up on the latest episodes (S.8) he says to Clara that if the TARDIS was to show it's true size it would fracture the surface of the earth.

  • But is it bigger than other (higher class) TARDISes?
    – Valorum
    Commented Oct 27, 2014 at 23:38

Wasn't there a episode a couple of years ago where they went into the future where the doctor was dead and the full tardis was acting as his tomb? Also I recall a old episodes that showed the layout as a pyramid?

  • This is true, but could you provide some citations, and perhaps phrase the questions as statements, to make it more clear how big the interior actually is?
    – Adamant
    Commented Sep 30, 2016 at 20:36
  • The episode that you are looking for is probably ”The Name of the Doctor.”
    – Adamant
    Commented Sep 30, 2016 at 20:37

The question of size and mass makes sense in universe. Time Lords can alter the size (dimension) of the TARDIS irrespective of the mass of the TARDIS. (Time Lords being dimensional engineers after all!) So while the TARDIS has infinite volume it does not necessarily have infinite mass. This then allows for them to eject a quarter of the mass of the TARDIS even though it has an infinite volume in it's interior.

  • Whilst you are answering the question here you seem to be mainly focusing on the mass of the TARDIS rather than its interior size. It might be better to re focus your answer on the size and also edit in some quotes to support your claims.
    – TheLethalCarrot
    Commented Sep 8, 2019 at 21:54

It has been claimed that the interior of the Tardis is infinite. Other answers mention the doctor claiming that at least once.

Someone asked if that makes the interior of the Tardis larger than the universe.

I once read that it was possible for there to be different infinites, all infinite, but some larger than others. So Adric might have been wrong to say that a quarter of the mass of the Tardis couldn't be infinite.

At the present time it is unknown whether the universe is incredibly vast but finite, or infinite. Thus it is possible for both the Tardis interior and the universe to be infinite, and for the universe to be larger than the Tardis interior, or the tardis interior larger than the universe. If the universe is finite, it might be contained inside the Tardis interior somewhere, while at the same time containing the Tardis exterior (which is almost always within the universe) which contains the Tardis interior. And so on and so on.

And since all the other Tardises also (almost always) have their exteriors within the universe, if the universe is inside the interior of any Tardis it could also be inside the interior of each and every Tardis. So each and every Tardis could contain the universe, which contains the exteriors of each and every Tardis, and each and every Tardis interior would contain the universe and each and every Tardis exterior, and so on and so on.

I think I remember an episode, possibly "Logopolis" where the Master did something to the Doctor's Tardis, putting it inside itself. Thus when the doctor went out the door he found himself still in the Tardis, an outer Tardis you could call it, and when he went out the door of the outer Tardis he found himself in an even outer outer Tardis, and so on.

Earlier, in the 4th Doctor episode "The Invasion of Time", Sontarans pursued the Doctor into the Tardis and he led them on a long chase through brick rooms and corridors, filmed in an abandoned building. And I think that was my first hint that the Tardis interior was not merely ordinary house sized but probably at least labyrinth sized or Pentagon sized or possibly even Death Star interior sized.


Big enough to compress a "sun" in one room of the Tardis but also small enough that you can't fit a "piano" through the front door

  • 2
    Please can you add a source for these claims, e.g. by quoting from an episode (or book, comic, whatever) where a character says so?
    – Rand al'Thor
    Commented Jul 5, 2019 at 9:25
  • 1
    Being unable to fit a piano through the front door says absolutely nothing about how big the interior is.
    – F1Krazy
    Commented Jul 5, 2019 at 10:28

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