I have a hobby of creating exotic starships too, and I like to be thorough about their schematics. When I go to figure out what kind of mass they would have in real life, I pretty much use the rudimentary method of figuring out their dimensions, what they're made out of, and use that. I'll apply the same method here.
By my crude measurements, I'll say a SD is 1600x 800 x 300 meters (nice, easy numbers to work with)
that is 3.84 e8 m^3.
I'll treat it as a pyramid because that seems to be what approximates its shape the closest. So I divide this by 3. (( L * W * H)/3)
1.28 e8m^3.
Since Mike, for purposes of discussion on his site, likes to use iron construction at 10% solidity, and the density of iron is 7800 kg/m^3
9.984 e10 kg
about 100,000,000 tons.
Personally, I don't know how massive the ship's neutronium armor would be. I don't know that it would be more than a small percentage of its mass, however, and since I know nothing more, I will confidently stand on the above answer as a rough estimate.
SW ship hulls and mass
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