Board Thread:Warhammer 40k General Discussion/@comment-86.10.75.96-20160401182432/@comment-4851119-20160402132417

Impossible to say exactly because as far as I know we don't have a source which tells us the physical properties of the materials which make up the armour. If we knew the density of ceramite, and the actual ratio of "armour" to "power" (i.e. how much of the volume of a standard suit of armour is actually ceramite armour plating as opposed to internal systems) then a vague estimate could be made, but we don't know these things.