The height is mostly in the edges and the fold under - the shape is much like a dinner plate upturned over a soup plate, the dinner plate being the top of the cap.

Mathematically the rate of change in stitches is slightly different between the top disc and the bottom ring, there is more distance between changes in the ring than the disc as the ring is actually part of a cone.

I should have explained that first - but I see required shapes and proportions without any real effort, and then try to explain them in terms of pi, d or c and often the result is an expression close to in the listeners.

Anne the Pleater :ootd: