I did. In two posts. In this thread.
Defiant Class (Scale 3): 170 x 134 x 30 m, mass 355,000 t
Nova Class (Scale 3): 165 x 62 x 34 m, mass 127,000 t
NX Class (Scale 3): 225 x 136 x 33 m, mass 280,000 t
Constellation Class (Scale 4) : 231x135x65 m, mass 280,000 t
Defiant and Nova are for reference only; Defiant in scale 3 seems like an odd choice and is probably because the ship is so tightly packed and has such a small crew.
Look especially at the difference between the NX Class and the Constellation class. Yet, maybe, since Miranda Class (230 x 127 x 51, 520,000 t) is also scale 4, Constellation should stay scale 4 and NX class should join it?
Anyway: The point I’m trying to make is that scale is a representation of size, yet size does not only comprise dimensions (especially with the huge nacelles standing out, mass seems the better number, anyway), but also, e.g., number of crew or certain abilities. It is a rough estimate, calculated by rule of thumb, not by strict measurements.
STA is a narrative system, aiming to support, with its rules, narrative play. It is not a simulationist approach (I refer to the GNS model, here). Thus, players are even encouraged to use quick estimates and (while they may do so, if they choose) not necessarily need to calculate any small detail.
Dimensions are Length x Beam x Height, source for all numbers is is ditl.org