The thing is, when Lagann links up with Gurren, Gurren's limbs are destroyed and replaced with longer, more in-proportion limbs. On another occasion, Gurren comes up to Enki's shoulders even with his smaller limbs. I dunno how accurate any of the scale in the series is, but a full sized person can fit in GL's hand and Lagann's cockpit can only comfortably seat a single adult.
Well, after doing the calcs, Tengen Toppa is some 2.703 x 10^16 times larger that Chouginga. More or less the same relation between Chouginga and a sulphur ATOM. So, a comprehensive scale with that is pretty much impossible.
just draw the dotted line go into nothing on a zoomed in ttgl foot, as to emphasize this fact. 2things: 1, how the fuck do you have the time to actually do science math on an anime, and 2, how many laws of physics did ttgl brake in his big battle against grand zamboa? seeing as you have no social life you should be best to answer this question, but then again, who among us do have one?
I had the time because I am used to do small math in my studies, and it only took 2 minutes. C'mon, it was only doing some divisions and looking for atomic diameters in Wikipedia to have something to compare. And, I guess they didn't break, well, friction, I guess. Oh, and, social life, I happen to have it. I just happened to have curiosity to know this.
GL's size fluctuates depending on what's cooler. I mean, the Gurren is slighty taller that the King Kittan, going by episode 8. But, when the KK and the GL are shown together in episode 21, the former barely reaches its hips.
There's no real definitive scale. All I know is that when Lagann links up with Gurren, Gurren's limbs are reformed, but the chest and head stay the same. And in the final episode, Ark can fit in CGGL's mouth with room to spare.
this is how you explain it: tengan toppa gurren lagann is SO large that it's punches move fater than the speed of light. and i mean that. TTGL and Granzamboa were crossing that galaxy which was bigger that the milky way, which i remind you is 100 lightyears across roughly, in a matter of seconds. PHYSICS BE DAMNED!!!!