To all my grammar-nerd writing buddies because I've been confused on this: SIZE vs. SIZED.
It is most important to make a guideline and stick to it. Don't use “fullsize car” in one paragraph and “full-sized car” in the next.
Hyphens are squishy and hard to pin down.
– Generally, you CAN use a hyphen if using a full noun before size/sized, which makes it a hyphenated compound word. You can also leave out the hyphen and make it a non-hyphenated compound word. This can get odd-looking, so be careful about omitting.
– Generally, do NOT use a hyphen if using a prefix before size/sized, like “mid.”
SIZE vs. SIZED:
If you are comparing two things that have no direct relationship as a metaphor = -size
If you are saying that something was purposefully manufactured/made to be an standardized size = -sized