How big is small, normal, large and xlarge?

Question

I know that there is a section in http://developer.android.com/guide/practices/screens_support.html about the categories of the physical screen sizes but the diagram is very rou

Answer 1

The Android Compatibility Definition only states that devices have to be greater than 2.5". It does however also require compliance with the multiple screens support doc so while these sizes are rough (as you pointed out) this is all you can rely on and probably the best information you'll get. I believe Google is intentionally being vague here. You (as a developer) should not need to worry about exact physical screen size.