Right now, there is only one trait for describing a profile character's size: body height. The trait options for Body Height work relative for your gender and species. Most of the time, this works just fine.
If you look for Tall profiles, you'll find profiles that are generally tall, relative to most people. Same with short.
The issue comes into play when a profile has a more exotic species. Under the current system, a 6-inch pixie should be listed as Average in size. A 600-ton dragon is likewise Average. Giants are supposed to be listed under Average as well. It's only when you deviate from the norm of your particular species and gender that you use other trait options.
That's not very intuitive, and indeed if you look at profiles, you'll see pixies listed as Micro, yordles listed as Short, orcs listed as Tall, etc.
Simply changing the description of Body Height to reflect absolute measurements is an option, but it has some drawbacks. 5'11 is on the high end of Average for a male human, but it's easily on the Tall side for a female human profile.
So my proposal is to have both. Body Height (Relative) is how tall a profile is compared to other members of the same species and gender. Body Height (absolute) is how tall a profile is in objective terms.
So for instance, a fairy would have a Body Height (Absolute) ((BHA)) of Tiny and a BHR of Average. A four foot dwarf would have a BHA of Short and a BHR of Tall, because they're heads and shoulders taller than other dwarves. And so on.