Floor height?

Maybe a noob question, but is there a way to get the Floor height from one of the Vive objects? I recall when i did the SteamVR calibration i had to place the controllers on the floor, so i suppose that information is stored somewhere?

When i put my headset on the ground, it usally reads 10 units “Get Orientation and Position”:Z

So im 182 cm in height, but when i stand upright looking forward, it reads 170ish, so if i add those 10 units to it, i get my real height (more or less). So i wanna use this to calibrate the size of the world to my size, either from head height or distance between hands in a T-Pose. Or possibly the meanvalue of those two relative to my Character ingame. So far i’ve used the hands distance to do calibration, but it’s not always precise, so i thought of adding in also the head height to get a better fit maybe.

Hope someone can explain how to get the floor height.