Thanks folks - I know this is an issue that has rumbled round and round for years and is not helped by slight differences between Daz Studio and Poser and, I think, some earlier versions of Poser itself.

I was curious as to how much reliance I could put on the ruler props I had and, using JoePublic's method (neat!) the answer would appear that they are both inaccurate in P2012 (although Dr Geep's is closest).

By taking a cube primitive, moving it on the y axis 1 unit (I am using feet as the measurement in Poser settings here) and then scaling a second cube primitive accordingly I discover that 1 foot / 12 inches requires that second cube to be 116.8% on the Y scale.

Now placing a cube against V4.2 at 100% and stretching the y-scale on the cube until it bi-sects the top of her head I get a y-scale of 734.4%. In my picture I've reduced the x-scale of both cubes also, but you get the idea.

Now, by my reckoning, if 12 inches = 116.8, then 1 inch = 9.73, so I can calculate what 734.4 equates to in inches.

This comes out with a height of just over 6 feet and 3 inches (just under 6'3 1/2"). Now, I'm not foolish enough to claim that this is a definitive answer, but it's useful to know as a starting point for relative sizes.

I could, of course, now measure things more accurately, using Joe's method, and scale my ruler props accordingly...

(stands back to observe the debate further...)