Officially they're non-scale. Practically they work out to just a little smaller than 1/144 scale - ie. they are comparable to HG scale in Gundam plamo (though as stated they're typically a little smaller than their model compatriots at HG, they would look fine displayed next to them). Note that this applies mainly to the Gundams - you'll find that the other RD figures tend to fall in the same ballpark size as the Gundam line even when in "real life" they should be bigger or smaller - ie. Code Geass RDs are about the same size as Gundams and while L-gaim figures are somewhat taller, they are not tall enough to be considered properly in scale with the Gundams.