No substance is calculated that way. Mass per unit volume is called the density of a substance or object, which is a property or unit of measure of a substance.
There is no substance which is - or even can be - calculated by its mass by volume.
It's not exactly a "substance" but Density = Mass / Volume
Density is the mass per unit volume of the substance and for any "lump" of the substance may be calculated by Mass/Volume in the appropriate units.
The relation between mass(M), density(ρ) and volume(V) is given by: M = ρ x V. So mass can be calculated only if both density and volume are known. Density is a measure of amount of substance per unit volume, so mass can't be calculated until the volume of substance is known.
The mass in a given volume can be calculated from the density of the substance. Density = mass/vol so mass = density x volume
Density is the mass of a substance divided by the volume of that same mass of substance.
When we divide the mass of a substance by its volume we get its density.
When we divide the mass of a substance by its volume we get its density.
The density of any substance can be easily calculated knowing that it is defined as the ratio of the mass of a substance divided by the volume it occupies.
The mass of a given volume of a substance depends completely on the density of the substance being analyzed. Density = Mass / Volume
Density of substance = mass of substance / volume mass of substance = density x volume
Measure the mass and volume of the substance, then divide the mass by the volume.
% of volume = 100*(volume of substance that you are interested in)/(total volume) % of mass = 100*(mass of substance that you are interested in)/(total mass).