My largest DNs have 22 Hull, the smallest BBs are 19 hull.  My only cruiser is a CLAA and it has 12 hull.  My DDs have 7 hull. 
As for Carriers, I have a 14 Hull CV, 12 hull CVL, & 8 hull CVE.  This works for me...

Every time this topic comes up, I mention this... so why break with tradition?

Historically, dreadnoughts are (rather primitive) battleships... When/how did the idea that a "dreadnought" is a "large battleship" come from?

I would also note that in Star Fleet Battles, the original dreadnoughts came first, followed later by a small number of even larger ships that got called battleships, so whether by purpose or accident, they managed to preserve the historical relationship of which came first and which was bigger.

I want to blame Starfire for this.

But, I do seem to remember coming across the term "Dreadnought" as a super-powerful ship in a Golden Age of Sci-Fi book a long time ago, possibly from the Lensman series?

Besides Dan, it just sounds cool.   
Cheers,
Erik

Nobody wants to guess at the size of a Battlestar or Star Destroyer? They seem like really big ships, like much bigger than Star Trek ships, but thats just my feeling from looking at them. I'd think a Battlestar might be large battleship size, 20-24 hull.

Got comments and a question about mass and hulls...

Having been in the Navy, and served on a carrier, I can tell you those things are big. Once, we were alongside one of the resurrected battleships. Those guys were physically a lot smaller than a modern carrier. But whereas the carrier has a lot of empty space (the hangar deck), battleships have lots of dense armor.

If I remember correctly, those battleships were around the 45,000 to 60,000 ton zone. I think the Yamato was close to 70,000 tons. The WWII cruisers were closer to 15,000 tons, maybe more fully loaded. The huge Alaska class was often called a battlecruiser, and weighed in at around 30,000 tons.

My carrier, an older Forestal class one, was around 70,000 to 80,000 tons. Compare this to the biggest modern carriers that inch over the 100,000 ton mark. Wow. On the other hand, WWII destroyers were 2000 tons or less, and modern cruisers are rarely larger than the 5000 ton range. Some are, in fact, destroyers that have been redesigned as cruisers. The Ticonderoga class is just under 10,000 tons.

I threw these numbers out there to show what an incredible range of mass numbers you get on real naval vessels. If a "modern" cruiser in the 10,000 ton range is 10 hull, then modern carriers are hull 100.

However, I think this scale is probably not correct. Is hull linear to mass, or is space requirement linear to mass?

If its spaces, and the cruiser is around 10,000 tons and 2000 SU, this is roughly a 5 tons per SU ratio. A large 100,000 ton carrier would be 20,000 SU, which is approximately 60 Hull. A 45,000 ton battleship would be around 30 Hull or a little more.

Thats still a MUCH larger hull ratio than what people have been posting, where typically cruisers are 10ish and battleships are no more than 20ish.

My question is, is there something wrong with the way I am looking at this? Or is it just that in the sci-fi universes, the battleships are really closer to battlecruiser size compared to cruisers.

(Afterthought: let me quickly add that I KNOW I am comparing wet navy to spaceships and real world to sic-fi, and Starmada being what it is, I can define things how I like. I just happen to like having my various ship classes bear a passing resemblance to their relative real-world sizes...)

I think of SUs as being the closest approximation to hull displacement.

FWIW, we're working on Grand Fleets (3rd ed). With the scale we're using, a 1000-ton destroyer gets 3 hull, while Yamato gets 30. A 100-kton carrier would get 40.

Going with your second question - The key for me on what 'size" is a star destroyer is the size to make a game 'fun'.  I know this sounds like a cop out and it kinda is, but I'm assuming that each player (for convention games) gets between 2 and 5 ships costing about 1000 points.  So my two star destroyers will be around 500 points each.  Cylon will be around 330 points (since I have 3 of them) and so forth and so forth...

Make the game fun first and then worry about how many hull points a start destroyer has!

That's not really correct. Here's the actual history of the terminology, w.r.t wet navies:

The term "battleship" derives from "line of battle ship", an alternate term for "ship of the line". "Battleship" superseded "Ship of the Line" in the late 19th c.; basically, as steel capital ships began to become standardized. So, "Battleship" as a naval ship classification predates "Dreadnought".

In 1906 the British introduced the first of a new type of battleship, being much larger than her predecessors and carrying a uniform armament of large guns (preceding designs had generally carried three or four different sizes of weapon). This was HMS Dreadnought (the name was just the next in the ongoing British battleship name progression; it was a traditional Royal Navy name and an HMS Dreadnought had fought at Trafalgar), and all all-big-gun battleships became known in the English language as "Dreadnoughts" or "Dreadnought Battleships". So, dreadnoughts were a large and powerful sub-type of battleship. Following this pattern, "Super Dreadnoughts" were the next big leap in battleship size (HMS Orion, ~1910) and were a sub-type of both battleships and dreadnoughts.

By the Second World War, virtually all of the old pre-dreadnoughts were out of service and the term "dreadnought" was now far less useful in distinguishing battleship types and became less common, although Bismarck, Yamato, etc, were all still dreadnoughts in any sense of the term.

How all that translates to a Sci-Fi setting is of course going to vary, but that's the history of the terminology.