How much space does matter take up?

Matter is all around you. It is simply and object so for an example- a pen. How big the pen is, is how much space it takes up. Not very much space is being taken up. The bigger and object the more matter it has and the more space it takes up.

Most of matter itself remains empty space. The nucleus of an atom is orbited by a cloud of electrons. Only a tiny fraction of the total volume is consumed by these elementary particles. But assuming the matter forming a rock or a star is solid (and some big stars get compacted into lumps of neutronium--the most compact form of degenerate matter this side of a black hole), matter itself occupies only a tiny fraction of the total volume of space. Even considering that much of interstellar space may be not entirely void, but includes cosmic rays and hydrogen atoms of densities of 1000 atoms per cubic meter, Most of the volume of interstellar and intergalactic space remains void of anything.