Ultrasound of right kidney finds "upper pole calculus [that] measures .6 x .5 x .4 cm." I am trying to determine the size of the stone, its diameter and area, and then convert that number to mm, but I don't know what the given measurements refer to. For non-spheric solids, i.e. rectangle, it would be length by with by height etc. But for spheres?? I was a humanities major. Any help would be greatly appreciated. Thank you.