For SARP purposes, BWH is a completely optional character attribute, and putting it on your character biography page is mainly useful for fellow players to visualize your character's shape, and for artists commissioned to draw your character. We hope you find this page educational and informative and remind you that body size doesn't affect how awesome you are.
Measurements are fairly simple enough: Bust - Waist - Hips.
A female human's “measurements” (BWH) usually refers to the following:
With a classically-figured woman of average height (which I presume is around the 5'-5'6 area), I have heard that optimum measurements are somewhere in the 36-24-36 area. This is going off memory, so I could be way off, but generally the waist is the smallest measurement while the bust and hips are close to being the same.
The “ideal” waist-to-hips ratio is 0.7 (the waist measurement is 7/10ths the hips measurement).
If you want more examples, I took a wild guess and found that clothing sites have the best resource. Take your pick: preppy clothing store websites, adult sportswear websites, the Speedo website…basically anything where you would need to know how to find your measurements and then need a chart to match your measurements to a clothing size.
Hard numbers for bra sizes are like this: You have the initial diameter of the rib cage (standardized of course) which is usually an even number. Adult sized bras in the USA start at 32 and go up in 2 inch increments. Standard sized bras are: 32; 34; 36; 38; 40; etc. Keep in mind that this is how wide around someone's ribcage the bigger this number is, the “thicker” the person's body is.
For Measurements you take the Bra band size (The rib cage diameter) and add the inches from the Cup size (A= 1; B=2; C=3; D=4) to that base number to get the bust measurement. So a 32 with a B cup would be 34in in her measurements.
Bust measurements tend to confuse people due to the fact that they are uncertain of how bra sizes work. The number represents a band size, the diameter of a woman's chest. The letter represents the cup size which is how many inches from the chest the boobs are.
Cups sizes tend to equal this by European and American standards (Japanese bra sizes tend to run a cup size SMALLER meaning an AA cup would be an A cup):
So as an example, Chiharu wears a size 32B bra. This means that the diameter of her chest is 32 inches and her boobs are 2 inches from her body. This would make her chest measurement 34 inches.
AA-Cups are virtually flat-chested. Common for prepubescent girls, but rare among developed women.
A-Cups are the smallest size considered a “true” cup size, since it is the smallest state in which the breast becomes pronounced, though is often still too small to make a significant bulge unless the person is wearing relatively form-fitting clothes. Uncommon among adult women, but common among mid-teen girls.
B-Cups were the most common cup size and made up roughly about one third of adult women. Typically B-cups size is much more visibly pronounced, and is the smallest of the “grabbable, a-palm-full” cup sizes.
C-cups are arguably the new most common cup size. While their occurrence is similar to that of B-cups, if you look at any modern fashion or swimsuit magazine cover, the odds are she's a C-cup; both B and D are much less prevalent among models.
D-cups are typically those “wow, that's big” cup sizes that are very roughly the size of a sweet melon. Once breasts reach this size, it's fairly common to start suffering minor problems (sore backs are common without support, much harder to fit bras properly, possible sagging). The occurrence of D-cups is uncommon; it appears only slightly more often than A-cups.
E cups (aka DD) and all sizes larger cumulatively occur almost just as often as D cups. Still, for the sake of having soldiers who can actually fit into power armor, or a soldier that can actually move without encumbrance I think this should be reclassified as rare.
According to a survey by bra retailer Intimacy1), the average bra size in 2013 was 34DD. Interestingly, in 1992, the average was only 34B.
Star Army has a random generator for BWH, cup size, and height here: Random Body Measurements Generator