Just how big is the Tardis on the inside? No "Bigger than on the outside" please! I have seen some fan made blueprints that show it to be the size of a small city! Is there any canon that tells or shows the true internal dimensions?

I like to think there's a door to another universe somewhere inside it. So to answer your question - bigger than a universe. Seriously though, I'd like to think of it as being the size of a small city. Maybe a few Time Lords got lost in there somewhere...

I would suggest watching the DW Confidential for The Doctor's Wife. It is discussed at length. No real conclusion, it has varied over the years. I don't think we'll ever know. Its size will always depend on the needs of a particular story. I mean watch The Invasion of Time. Big but like a 1950s hospital.

I always thought it was the size of a planet in there.

Where did I read that...?

The door to another universe is the Police Box door. The TARDIS exists in its own pocket dimension, as I've always understood it.

Thread about the mass of the TARDIS here: http://forums.digitalspy.co.uk/showt...623&highlight= (was just going to repost some of the info here, but I felt a bit uncomfortable taking credit for it).

I see it as infinite. When they "jettison" a room, I'd imagine it would be replaced somewhere - like the TARDIS "saving" the old console rooms.

you're probably thinking of the size of Marvin's brain

How big is the TARDIS?
The only answer must be "as big as you want it to be"!

I guess it's a "Timey wimey thing then?

Very good answer!

How many dimensions? How many universes? I think I'll go and have a drink with Granny Mc' Smith.

Tardis dimensions are relative - they can't be measured as absolutes.

Well, if you take into account everything we've been shown or told about it in both the classic and new series and the various other media (particularly the books), it may not be infinite but it's pretty damn big. It not only has miles of corridors and rooms including at least 30 control rooms (at least three have been shown to exist independently of each other in the show and there was also a Tertiary Control Room with a console made of stone in one of the books), several wardrobe rooms (or possibly just one really big one which regularly reconfigures itself), a library, a laboratory, a kitchen, a swimming pool, a power room disguised as an art gallery, a boot cupboard kitted out like an Edwardian drawing room, a cricket pavilion, a sick bay, several warehouse sized storage bays and extensive living quarters, it also has several different levels including an attic and a basement, not to mention Cloisters and a vegetable garden. In the eighth Doctor novels there's also a doorway which appears to open out onto an open hillside covered in butterflies and a garage where the Doctor keeps a VW Beetle. The architecture seems to shift around at will (whichever control room is in use, for instance, maps itself onto the exterior doors) and occasionally to loop back on itself, and the Doctor himself hasn't explored all of it. I'd actually like to see a two parter set just inside the depths of the TARDIS...

Hah! Nice one Ting! I'm sure they could do a full two-parter just set in the Tardis alone. It wouldn't cost any more than a regular episode - they could film 'anywhere'!
I also think that Tom Baker and Peter Davison reduced the Tardis in size somewhat - when they started Jettisonning bits of Romana's bedroom, the Zero Room and lord knows what else to propel the Box in a new direction!!

Just to throw a philosophical spanner in the works....

The Tardis can add and remove "rooms" and rearrange it's interior. Imagine that you enter a room with ten doors. There is a room behind each door.

Except that there isn't - because the Tardis can just create each of those rooms as and when thay are needed.

You could walk through the Tardis forever and never visit the same room twice - unless you wanted to - and there would never need to be more than two rooms - the one you leave and the one you enter.

The space would be limited - but it would appear infinite to you as an observer.

It's relative to your perception.

A
Are you talking about Quantum physics?

A slightly 'off topic' bit here. The original Doctor always made a point of locking the Tardis doors when they landed somewhere. In following series - they tended to walk off and leave the doors wide open, regardless of who might walk in there! This happened lots of times - does the Tardis have an automatic door-shutting mechanism after so many minutes?

Not really. In quantum theory, the room would have to cease to exist when the new one was created - they would flip states instantaneously.

I'm saying that the Tardis could simply create, delete or alter rooms in real time according to what was required and to us, that would appear like an infinite number of rooms.

In simple terms - think of a train that is exactly 20 track sections in length. If you had 21 pieces of track (and were really quick) you could keep taking the rear-most piece of track and placing it in front of the train. You'd never have more than 21 pieces of track but the passengers would simply experience the train as travelling on an infinitely long track.

What happens if there are several people in different areas of the TARDIS at the same time, though?

http://ironmongery-solutions.co.uk/B...r-Closer-3.jpg ???

Idris will protect herself.

Thanks. But what happens if the train/ TARDIS, goes into reverse mode?

Long live the Hartnell party!